Those tremolo/vibrato settings are not exposed by either the SBI format or S3M AdLib patches, as far as I'm aware. I wasn't even aware that they exist and that the default tremolo/vibrato depth are different from the values specific in the tooltips / manual. I will double-check and adjust the documentation if necessary, but it's unlikely that these values would become adjustable because ScreamTracker doesn't support them.

Manual has been corrected. But as mentioned, for the time being it's unlikely that this will become configurable as neither the S3M nor SBI patch format actually dump the register (0xBD) that contains this information.

It's also worth nothing that this is a global register, i.e. it applies to all active voices (you cannot have one patch use tremolo at 1dB and another patch at 4.8dB). Given that I want to move MPTM into the direction of using one emulator instance per instrument, this wouldn't be an issue if we decide to implement this flag in MPTM format, though.