Right now the following games are supported:

Aleste
Alestegaiden
Andorgynius
Arsenelupin3
Ashiguine2
Blowup
Craze
Crossblaim
Dirdeaf
Dota
Dragonslayer4
Druid
Eggerland2
F1Spirit
Familce parodic1
Fantasmsoldier1
Firebird
Galaga
Galious
Girlyblock
Goemon
Golvellius1
Goonies
Gradius
Gradius2
Gradius3
Gryzor
Ikariwarriors
Kingkong2
Kingsvalley2
Knightmare
Metalgear1
Mon mon monster
Mrghost
Nyancle racing
Outrun
Parodius
Penguin adventure
Pippols
Rambo
Rastansaga
Sdsnatcher_Init
Spacemanbow
Starquake
supercooks
Superlaydock mission striker
Superlaydock msx2
Thexder1
Thexder2
Undeadline
Usas
Vampire killer
Xak1
Ys1
Ys2
Zanac

you can download the latest file here

usage is simpel :
1) Put this file in your openMSX/share/scripts directory
2) Bring up the console and type in trainer_[your game] see the TCL file for exact names.

Please feel free to add cheats you have found using the cheatfinder

Very neat

Am I wrong or do some of them update the cheat values every frame?

yes they do update every frame....

I made this file until a solution is made/found trough some interface where you can actually choose cheats... after a game is auto detected. But I'm still working on a XML structure for that.

I just updated with 4kb more cheats