I had promised to test "in a few days" which became much longer than that (sorry). The test was not successful.
First, I found no option for "padding=", but there is a 'padsize' option, which will add a number of bytes to the end of the track. So I burned with 'padsize=33' and created a CD #2 image on a disk. I used my main work computer, which I've used before for lots of FC CD sets.
Mediacheck on the new CD failed with DMA on (my usual default), so either I've made some other kind of error in testing or this isn't going to help. Maybe others with different hardware will have more success.
For the record, booting with 'nodma' DID work for me, so I have a way to test CDs and install. I was just trying to understand what was causing the mediacheck failures.
Erik