Is there a way to override a Mac system font and use a different version

More info. It seemed rather broad to say Adobe isn't rending TrueType fonts correctly. That would cover thousands of fonts. So I opened Photoshop again and tried all kinds of TrueType fonts. Those installed with the OS, and many third party fonts. At any point size, fonts would line up as expected.

The only ones that wouldn't were the Avenir sets. So then I wondered why and looked at the hinting. And yes, all of those fonts in particular have odd hinting on the u.

Such as, here's hinting on the w. And it's basically the same with t, v, w, z and others.

So, why does the u have this oddball hinting riser? And actually, the hinting on the entire shape is out of alignment (high).

Anyway, that's where the problem really is. A bit of bad TrueType hinting that rears its ugly head at smaller point sizes.

Adobe appears to be the problem here. I looked at every style (regular, bold, italic, etc.) of Avenir Next Condensed in FontLab 8. The u is exactly on the x height line. As is the v, x, z and others with a flat, horizontal top. Those that go over the x line are the ones with a curved top, like b, s, a.

Here's the regular shape:

If I use any faces of this font in Viva Designer (an InDesign work-alike app), the font lines up as expected.

When I output this text to a PDF from Viva, it also remains lined up when opened in the free Acrobat Reader.

But, when I open this same PDF in Photoshop, it renders incorrectly:

And then there's another "but". This only happens in Photoshop under a certain point size. If I set the point size to 24 or higher, then they line up. Lower than that and it becomes uneven. And "but" again, the above in green was 60 point text out of Viva, and it still didn't render correctly in PS, though the font does if you're directly setting text in Photoshop at 24 points or larger.

I then wondered if Viva Designer would behave the same way. It doesn't. At nearly any point size, the text remains lined up. Only 8 point was very slightly off. The output to PDF remains identical to the Viva interface.

Pages and TextEdit fared the same as Viva. Small point size, slightly off. Larger sizes, perfectly inline.

Oh, didn't address the actual topic question.

No, you can't override the system fonts (any of them). As of Ventura and later, none of them can be disabled for any reason, or with any app. Which means any attempt to activate a conflicting font (same internal names) won't work.

As a test, I'm going to dump a PostScript OpenType version of the regular face to see how that works. TrueType has lots of hinting in the font. PostScript has much less hinting and the PS interpreter does most of the shaping.

Edit: Yup, that's it. An OpenType PostScript copy of the font works perfectly, even down to 4 point. Adobe's apps aren't rendering TrueType fonts very well. At least, not at smaller point sizes.

I'm kind of surprised Adobe tried to modify the font at all. It's a copyrighted font that belongs to Linotype.

So, if I understand correctly, even if I install an OpenType PostScript copy of the font, the system font will override that and I won't be any better off?

If an OT PS version has the same internal names, then yes, you won't get anywhere.

In my little test, I changed the internal names of one font and saved that to an OpenType PostScript font so I could activate it alongside the already installed system font. Saw that it worked, and then deleted it.

Per the above about hinting between the font types, TrueType has lots of hinting since it all has to be part of the font. PostScript has minimal hinting within a font and the PS interpreter does the majority of the hinting work. So, when I saved a TT version of the font out to OT PS, FontLab basically stripped all of the current hinting and replaced it with automatically applied PS hinting. Which eliminated the u issue in the process.

What happened overall is the apps that didn't display an issue with the alignment, those apps were paying attention almost entirely to the font metrics, and little to the hinting. Adobe's apps do kind of the opposite by giving equal weight to both the metrics and hinting to determine how the letterform should be presented.

Making sense of internal names is much easier if you see it. Here's the naming for Avenir Next Condensed Regular:

Note the family name. Every font in this set (regular, bold, italic, etc.) has the same family name, which causes them to appear as a group in your font lists:

I included some of the Bodoni fonts in the screen shot so you can see the two bottom ones must have different family names, which is why the fall separately in the list instead of being grouped inside of Bodoni 72, or Bodoni 72 Oldstyle. I didn't actually look, but I don't need to in order to understand why neither is in a previous group.

The family name wouldn't be the issue. That's just for grouping fonts in a list. If a PostScript version had any internal names identical to the Full name, PostScript or Style group names seen above, then you'll have a conflict with the system installed TrueType version and it won't work.

The good news (sort of), is there are OpenType PostScript versions of Avenir that do work since they have different internal names.

The problem will be finding a legal copy. Adobe's Font Folio 11 used to include AvenirLTStd in 12 styles. None of them condensed.

If you find a legal way to purchase the previous 22 font set of what used to be AvenirNextLTPro fonts, those would work. Otherwise, a trip to Linotype would be necessary.

They sell their fonts through Monotype and MyFonts. And not cheap. It's now 40 faces, and the Condensed Regular font alone is $98. And I can only assume these won't have the misalignment issue. But at least they seem to be the same as the older set of 22 OT PS fonts I have.

A lot of money, I know, but I don't see a cheap or easy way to avoid the Apple included TrueType fonts.

Adobe, and just about everyone else no longer support the old Type 1 PostScript fonts. But they all support OpenType PostScript. I use them all the time.

Thank you for posing your question very clearly. I think this is a question you would be better served if directed directly to Adobe.