I'm glad the adb flag is still an option, I had to use it to install the app for my ebike wheel which is the only way to adjust the assist level / Regen brake strength. Maybe eventually I'll try rewriting the app but I just don't have time.
So with adb I should still be able to install old apps? Also is there a way to back up my apps without root, since there's been some old apps that stopped showing up even for ones I bought when I tried to download them on newer phones.
Yep they give the command in the article but to install an APK, all you have to do is plug into a computer that has the APK downloaded and use adb install --bypass-low-target-sdk-block appname.apk
I used it on android 14 and it looks like it'll also work on 15
Until someone with a better way responds, you can copy files to your PC with the adb pull command. Here adb is a terminal command you run on your PC. App data files are mostly in /data/data/packagename on the phone.