I was told webMAN MOD already comes with CONFIG files (those installed by PS2CONFIG) for the PS2 ISOs and that PS2CONFIG is mainly needed on PS3HEN with encrypted PS2 games (which are in the ENC format and they're also inside the PKG one [the official PS2 Classics also have encrypted PS2 games inside the PKG file]) mounted by webMAN MOD so I don't need it since I have CFW and I don't have encrypted PS2 games (except inside some official PS2 Classics [the PS2 games I tried were in the ISO and BIN/CUE formats]).
It seems webMAN MOD's "Auto CONFIG" setting automatically looks for the matching CONFIG file in ManaGunZ's MANAGUNZ0 folder (I didn't even install ManaGunZ) and in webMAN MOD's UDPWEBMOD folder. If the PS2 ISO or BIN/CUE already has a CONFIG file associated, that file is used without having to perform said search. ManaGunZ allows to create CONFIG files.
EDIT: I bought an used PS3 since the previous stopped reading BRs, installed webMAN MOD and it hasn't been freezing my PS3 so maybe it was the previous PS3's HDD's fault. Anyway, I got used to IRISMAN so I uninstalled webMAN MOD again. To fix the PS2 games mentioned
here so that they can be played on CFW without (or with less) issues after being mounted by IRISMAN, their respective CONFIG files have to be downloaded from
here, they have to be renamed them so that their names match the games', their names also have to have ".iso"/".bin (if the "iso"/"bin" filename extension is in lowercase) or ".ISO"/"BIN" (if the "BIN" filename extension is in uppercase) before "CONFIG" to work and they have to be in the same location as the corresponding games (in the PS3's PS2ISO folder).
These CONFIG files can also increase frame rate in some PS2 games and they're the CONFIG files installed by PS2CONFIG (I deleted the latter since I have CFW and not PS3HEN, use IRISMAN and not webMAN MOD and I don't have encrypted PS2 games [except inside some official PS2 Classics]).