32-bit support is not coming back, and nor should it. Having a mix of apps means having both 32-bit and 64-bit copies of system libraries loaded in memory all the time, which is inefficient.
For security reasons, you probably should partition your Mac, run Catalina or Big Sur* on your main partition with your personal stuff, PGP keys, and other important things, and have a separate partition with Mojave for your legacy apps. If those are mostly games, then you may be better off with a Windows partition instead of Mojave, because that would support even more games.
One of my "important things" is a 32-bit app required for a freelance project. This freelance project also requires some 64-bit apps, so I don't see how two partitions would help here. Am I missing something? (Sincere question -- I'm looking for a new solution because I know Mojave won't be supported forever.)
If that 32-bit app has a Windows version, you could run it on current macOS using CrossOver. Performance might take a hit depending on what you're doing, but the MacBook Pro M1 runs Windows games fairly well in CrossOver. Wine might also work.
If the app only available for 32-bit macOS, I suppose your remaining options are running Mojave in a local VM, or in the cloud (AWS offers Mojave instances for example) for your freelance work.
Out of curiosity, is this an internal enterprise app, or a consumer app? Most consumer apps have alternatives for 64-bit macOS.
> I know Mojave won't be supported forever.
It's unlikely to receive further security updates at this point.
If you're not on the latest macOS, you're not getting all the security updates. You will still get many security updates if you're one version prior (Big Sur right now), and if you're two versions prior you might get a few updates (Catalina). But you're unlikely to get updates to Mojave after this year.
Oh, I don't really care about MacOS that much. I've already moved on to Linux, which has much better support for games and legacy software (along with the development I do every day for, y'know, work). I just keep the old lappy on Mojave because it reminds me of better times. I never really do anything beyond basic text editing on it anymore.
For security reasons, you probably should partition your Mac, run Catalina or Big Sur* on your main partition with your personal stuff, PGP keys, and other important things, and have a separate partition with Mojave for your legacy apps. If those are mostly games, then you may be better off with a Windows partition instead of Mojave, because that would support even more games.
* A1502 does not get Monterey, I think.