Are there any different types of glass that are compatible or mixable? (i.e. can you put a layer of clear borosilicate over soft glass? etc?)

The simple answer is no.

What a person can do is slowly move up the chain of compatibility.  While 33 and 34 are not comparable fully, they will work, then you can do 34 to 35 and move all the way up to 104.

This would only make a rod of different glass, and not worth anything other than a science experiment.