64 bit support?!...

It depends on the app. Some apps include a 64-bit version, most don't. See here for an explanation: https://portableapps.com/node/24371

Continuing on from the above post, the answer is yes, whenever required or beneficial. We've created a unique packaging that allows the 32- and 64-bit versions of an app to coexist as a single portable app install and have the launcher automatically select between them based on the computer you're currently using. If you've used our portable versions of 7-Zip, AkelPad, Daphne, Explorer++, JkDefrag, Notepad2, Notepad2-mod, On-Screen Keyboard, PeaZip, RawTherapee, RegShot, UltraDefrag or some others, you've been using the 64-bit versions of those apps whenever you're on a 64-bit machine without you ever needing to know or worry about it.

Some of apps, the 64-bit versions are required (JkDefrag, UltraDefrag), some have better performance (7-Zip, PeaZip), some enable additional features (AkelPad, Notepad2) and some are a combination (RawTherapee). We don't add the 64-bit versions of apps where there's no benefit, which is the case with the majority of software, as that would double the size of the app (slower download, slower install/upgrade, more space on your drive, etc) for no good reason. That wouldn't be very nice for our users.

Best of all, this is all automatic and you don't even need to think or know about it. You just get the benefit when you use it.