charles32k, thanks for the info - with that, I did a little RE and came up with a fix to always use standard controller. (It's in d_nes)
// Top Rider size / crc: 163856, 0xca1a395a
// Patch in standard controller -dink feb.25, 2021
// Game Genie code for other emu's: IUEOKOAL
// lda $494
// ora $311
// and #$10
//*bne 99c5 ; start pressed, next screen
// jsr 9f68 ; check if code entered on controller #2
// bcs 99c2 ; yes? start game with normal controller in port #1
// ...
//*d0 38 bne 99c5 -> d0 35 bne 99c2