Why is this app install failing as incompatible and can it be force installed? I've used the Yell app for ages (com.yell.launcher2). It's recently updated and should be compatible with modern android (and is listed as compatible with 4+). I'm using LineageOS (=7.1) on a rooted Samsung Galaxy S7, which is certainly up to date. But the installer (when I open the APK) says it didn't install as it's incompatible, which surprises me.

Is there a log, or a way to tell, what the exact conflict is, either via GUI or terminal, and based on that information, is it likely that I can force it to install (perhaps it won't work once installed, but I suspect it will, but for sure it can't run if it doesn't get installed in the first place). If so what might work?
Install this APK with adb install from your PC, or pm install from a terminal emulator on the phone. This will give you the reason of failure. Alternatively, you could also search through the log output of adb logcat, though this approach is more tedious.