Bios Switch for Mega CD pal or NTSC

In other words I need a bios from an other country first. For example I have an pal Mega CD 2, I need an jap or us bios. Is this right? But this tutorial is only for 2 bios at the same time. It is possible to use all three country mods?
the tutorial as shown is for my multibios chip, which I sell.

it contains all 3 bios versions (us, jap, pal) plus a game.

in combination with a 50/60 hz switch on the MD/genesis, ALL games will work correctly.