MacBook Air vs. MacBook Pro as a backup machine for commercial printing.

You're running a business, and that assumes you need a computer that won't slow you down when the job needs to get done.

I suggest you go with a MacBook Pro that has the ability to actively keep its cool when the job requires it. The MacBook Air is a fine and capable machine, but as you know it has no fans and therefore it must rely on CPU throttling to remain cool under stress. Depending on the task at hand, it wouldn't be unexpected that passive cooling might not be adequate.

We'd all love to have a great system with no cooling fans, but I wouldn't put my business tasks in jeopardy by buying fan-less when a more robust option is not too much more expensive, imho.

You said: ❝ I just want to make sure I'm covered if I have to export a variable data pdf that might take 30 minutes to an hour to export.❞

So cover yourself. Business is business and you may even get to take a write off.

My fam and I have had over a dozen Mac laptops with fans over the decades and only one ever had any fan issues. That was a fan that eventually began to run a little louder than normal, but it wasn't obnoxious and the performance of the Mac never faltered. Mechanical fails can happen, and dust can be managed and mitigated.

All Macs will throttle their performance to keep hardware within its thermal limitations, exhaust fans notwithstanding.

Now with the new M series apple silicon and the superior efficiency, I am wondering if I even need to buy a MacBook Pro (with cooling fans) or if I would be well prepared just having a MacBook Air.

The answer to that question is "probably" provided you are willing to accept the tradeoff of maximum performance in exchange for portability, but since those are subjective interpretations only you will be able to make that determination.

Intel Macs were power-hungry beasts. Despite years of promises Intel was never able to achieve the power efficiency Apple demanded, and probably never will. Any M series Mac will run rings around the performance of any similarly equipped Intel Mac. Since Adobe is also notorious for less than efficient software, whether a MBA will be able to achieve the performance you seek is something that probably can't be answered.

Personally I prefer simplicity every time. The MBP is designed for maximum performance whereas MBAs are designed to favor portability. iPads don't have cooling fans, but they are no substitute for high end PDF manipulating workstations either. I suggest you purchase an appropriately configured MBA directly from Apple and put it to work immediately. Torture-test it yourself under real world conditions only you can impose upon it, and if you find it's not acceptable for your particular needs then return it to Apple for a full cash refund. You'll have fourteen days to decide.

For your stated uses, a suitably configured MacBook Pro is the better way to go.

The MBAir is designed for uber-portability not so much for performance or features. If you are concerned about performance on demanding jobs, then the MBPro is a much better choice than an MBAir.

MacBook Pro - Tech Specs - Apple

MacBook Air 13- and 15-inch with M4 Chip - Tech Specs - Apple

And you can compare the different models here -> https://www.apple.com/macbook-pro/compare/?modelList=MacBook-Air-M3,MacBook-Pro-14-M4-Pro,MacBook-Pro-16-M4-Pro