Hmmm... Was experiencing wrong BIOS settings on Android when copied over from the PC version.
After some testing I actually find out it was the ini file line-ending that was causing troubles. Android uses LF, while Windows read/writes in CRLF.
Simple fix, however: just change the file modes from "r" and "w" to "rb" and "wb".
Although that changes all line-endings to LF, thus requiring Wordpad on Windows to edit it, while becoming cross-platform ini files as a gain.
Edit: Just went the third path: reading can process all possible line endings(either CRLF(prioritize) or CR/LF(either one)). When a CRLF is found, it's parsed in that way, while just CR or LF also counts as a newline(So CR is a newline, LF is a newline, CRLF is a newline and LFCR are two newlines(first read as Unix-style newline, the second read as Macintosh-style newline)).
Writing the ini files still happens in the native format(either CRLF(Windows), CR(Macintosh) or LF(Unix)) for the current OS.
Edit: Also managed to fix the problem with the Sound Blaster that(according to old Dosbox source code) caused Windows 3.1 to hang when recording using 8-bit DMA(the first sample isn't read through Direct DAC).
The crash on the newly implemented instruction byte count limit was due to the counter&buffer being added during REP*eated instructions. Having fixed this, the counter won't (normally) trigger again and the POST succeeds 😁
Edit: Just tested cross-platform line endings by using the Android with Jota Text Editor to change to various line-endings(all three of them). It runs like a charm! 😁