Proper dyno tuning can take a lot of time and should be complemented with road tuning in such case.
There are hundreds of correction tables that when correctly done (lots of work), should be able to correct for variability between cars and/or readily be tweaked for the most common hardware upgrades. A quick dyno tune (<0,5 day) can extract extra power for a given individual, but the hardest work is making a resilient base tune that indeed can cope with being copy pasted and still work well, only needing to dot the i on a final dyno run. Guessing the wastgate control is causing headaches on this platform... If mk2 is better there (seems so from testdrive) that might be a compelling difference...
Never liked the smell of cancerous polycyclic aromatic hydrocarbons... mf works great as a driving tool and no tuning issues

, GRY has the handling edge in winter though for sure.