I have a hardware keyboard on my phone (Gemini PDA) that has Home, End and PgUp and PgDn keys that are entered by pressing fn+left/right/up/down arrows respectively. While ctrl+left jumps to previous word correctly, these keys behave as if I was not pressing the fn key at all (so while I am issueing "home", Termux thinks I am pressing the left key ignoring me also pressing "Fn" at the same time).
I will be happy to provide additional debugging, tried running xev but that is missing due to Android not running X.