I'd say a more appropriate metaphor is that of a 1980's Ford Escort Engine in a Model T body. The latter I can live with for some unknown reason, but it's the engine that worries me the most. And yes the amount of knock on effects from changes prompts one to say 'leave it alone' as from recent experience there's no telling what can go wrong with BIAB when new things are added. if there's to be any fundamental rethink I suspect it's going to have to involve recoding the entire program from the ground up.

Regards

Alan