I wrote here some time ago, the best tuning for an F56 is an engine swap.

As described I put a B48E on search, and found a crashed F54 JCW, I got the engine for a quarter of the 9000 Euros.
This will be planted into the Cooper, a Helix clutch kit incl flywheel, Quaife LSD, hopefully, work out well with the Getrag 6S manual.

This engine with its forged pistons, crankshaft, etc is the only way to get a long life B48 hotty, you can pump up to around 350 hp .

 

The buy of the used engine, came at the right time, as recently after 50.ooo km/h the clutch blew.

As everything is out anyhow, we can check the fitment of the Getrag Manual to the B48A20E. It would be also interesting to see if the # 27107646871Transfer box fits.

The B48A20E uses the BMW M pistons 9.5, the crankcase also improved you don't have to recast, as they did for the Dakar ;-)

 

a short reminder of what a 1.270 kgs 2.0 liter is capable of, and I see no problem for a GP3 as well