[OM] Teleconverter question

[ClassicVW]

Could someone please explain why an Olympus teleconverter is 'matched' to a 
certain few lenses? I understand about some lenses having rear elements 
that'll get in the way and can't be used, but we're talking 'optically 
matched', no? I assume other lenses may be used, just the results won't be 
'perfect'. Or am I wrong?
I have one or two third-party teleconverters, but I've never used them.

Thanks
George S.