Long story short my Japanese model 2 contains only a modchip. Playing CD-R games isn't its full potential.

I'm after region free. Best if I make sure every game possible can run in any form I'll see noticeable differences. So are there compatibility pros/cons of switches vs BIOS?

A few Saturn games behave like SMS/Genesis/GG and detect whether they're using Eng or Jpn mode, then start up accordingly.
Original run of Sōkyūgurentai is one of them. (more info and video about the partial English it contains)

50/60 hz would be OK too, just in case of any PAL optimized games I happen upon.

Suggestions of other mods I should know about are welcome too (digital audio? NTSC/PAL color switch? find out if my RGB cable is wired correct?). I'd prefer not to ship out multiple times. Already short on boxes as it is, so this might take me time to send.