Charlton, I tried AVAST for DOS botting from a CD and it worked a long time ago…
I think the problem is not on avast but on the specific version of DOS you’re booting.
You say after that there’s nothing else on the boot discs (A:/) that mentions loading any other memory managers, but how can you manage avast for DOS into floppies? Aren’t you using a CD?
Welcome to forums…