Why are Logic Pro 12.2 sessions overloading on M3 MacBook Pro?

I wouldn’t expect a few GB of files on the Desktop by itself to cause Logic system overloads.

I’d open Logic’s Performance Meter while the project is playing. That will show whether you’re hitting a Processing Thread limit or Drive I/O. Apple specifically recommends using that to diagnose overloads. Avoid system overloads in Logic Pro for Mac - Apple Support

Also check Logic Pro > Settings > Audio > Devices. If your I/O buffer is very low, raise it for mixing. Apple recommends a larger buffer and Process Buffer Range: Large for heavier sessions. support.apple.com

With GGD/EZdrummer plus that many effects, one heavily loaded channel or software instrument can max out a processing thread even when the Mac as a whole still has plenty of power.

One other thing: Logic Pro 12.3 is already available, so you’re one version behind. Back up the app/projects and make sure your third-party plug-ins are compatible before updating. support.apple.com

If you can post what the Performance Meter shows at the moment the overload happens, that would narrow this down considerably.

I can get to the Imgur links, although I wouldn’t rely on the video alone to pin this down.

Since you’ve already tried different buffer sizes and had the same problem in Logic 11, I’d do one controlled test before changing or buying any plug-ins: quit Logic, reopen it while holding Control, then choose Launch Without Audio Units. Apple specifically recommends this for isolating third-party plug-in problems.

If the overload disappears that way, then you know the next step is narrowing down which plug-in is responsible rather than the M3 simply not being powerful enough.

The recording delay may be related but could be a separate latency issue, so I’d tackle the overload first.