I have to confess I don't actually know what the implications of this are.....
More reliable wire feeding, rather than one set of rollers doing everything it’s like one set pulling the spool and set one pushing it to the torch. Can help with aluminium. GYS multi pearl 200.4 xl for example is 200a, ewm picomig 180a. Not sure there’s a massive choice of 4 roll machines with domestic supply capabilities. Probably some others out there,
Remember the euro tig torch isn’t cheap (or a decent one isn’t) and I personally don’t like lift tig, have you tried it? Might be worth popping into your local to have a go