Command Tab Hide?

I'm never sure why folks try to answer questions by telling someone they are doing things wrong, or question their reasons (vs asking clarifying questions). Regardless...

One example: Mail refreshes constantly, (as does Reminders, Calendars, and Notes, across devices. I prefer to laeave these open so they don't take any time to open, or refresh one they do open.

You might think of this as "Spaces" without the "Spaces" (which I find unpredictable, especially when using different monitors set ups.

BTW: Witch says it's on their feature list but no date...

Distraction; clutter,...

If you use Command tab to switch, it al isl still very accessible. Should be able to see a selection of apps, but option to hide when switching, just like you see them when selecting something that is hidden.

An "Option-tab" would be great.

I'm betting someone has written such a utility if it isn't built in and hiding. ;-)

Here is a semi solution via How To Geek:

"If clutter is a bigger problem than performance, you can also bulk hide applications. Bring up the application switcher again, select the application you want to hide, then press “h.” Every window for the selected application will be hidden instantly."

Command-Option-H hides everything except the front-most app; I asked about hiding just the app I'm switching from.

Example: I leave three apps visible across two screens. Merlin Project on my main screen with Calendar and Reminder on the side screen, side by side. I decided to check on Mail so a Command-Tab to Mail from Merlin. When I switch back to Merlin I want Mail to hide.

Hitting Option-Command-H would then hide Reminders, Calendar, and Mail. Not what I want to do.

Mansplaining??

I don't know?

I can be guilty.

I'm not looking for suggestions that deviate from the question.

I'm not looking for a Spaces solution (never predictable),

And even though I did not rule third party solutions out, using the soon-to-be macOS Shortcuts, Automator, or Apple Script is not 3rd party.

Mac OS X Hints offers some (are dated) suggestions.

Specifically, Quicksilver and Keyboard Maestro (rolled my own)

Betting Applescript and maybe even Shortcuts would work too.