I use my tablet with a keyboard (no mouse). The experience is so-so. For example, hot keys in Fennec work only in English layout, some keys work only when a particular widget is focused, etc. Some apps like SkyTube don’t support playback control keys (though one would expect this from a media app). Some apps (e.g. Termux) show useless on-screen controls, duplicating some hardware keys.
The bottom line: developers don’t test apps with hardware keyboards. Expect bugs and annoyances. But if you need to type text (even small amounts), hardware keyboard saves a lot of time.
if you have a matching USB OTG to USB Type A adapter you could connect mouse or keyboard to the smartphone and check with the apps you care about (hub might work too).
there are Bluetooth keyboards (some with mouse pad) which can be used with your mobile phone (prefer Bluetooth Low Energy over Bluetooth).
the Raspberry Pi could maybe also be used to get an idea of the look and feel.
I never did this myself so I don’t know what I’m suggesting!)
(Android - Raspberry Pi Forums could be a starting point)
I ran F-Droid using Android x86 for a bit about 4 years ago. The F-Droid app itself was one of the most fiddly ones but not totally unusable. Others like K9 were great.