ODBC driver settings for BLOBs

While inserting BLOBs into the database, I found that there are
dependencies on MaxVarcharSize, MaxLongVarcharSize and
UnknownAsLongVarchar ODBC settions. I need to set MaxVarcharSize or
MaxLongVarcharSize, dependent on UnknownAsLongVarchar, lower than the
smallest BLOB to be written to a lo column. In my case, the smallest
BLOB that will ever be written has 4 bytes, so 3 is the correct value
for me.
I went into the ODBC source, but couldn't determine if this would have
some other unwanted effects.

I now use MaxLongVarcharSize=3, MaxVarcharSize=254 (to keep Access
happy) and UnknownAsLongVarchar and hope the best.

I wonder if it really makes sense to deal with BLOBs different depending
on their size....

Regards,

Andreas