So some background...
I have seen some aftermarket pistons advertised as cross compatible for N14/18

I run a N14 Jcw R59 on track, and for extra fun it has the Rcz-R 270 hp spec turbo.
currently just ordered a set of 1302603 Catcam camshafts for a bit more extra poke.
i have this odd desire to not keep it stock but modify it as it could have been built...as a factory car with bits available within the group's supply chain, so it's genius or stupidity that has led me down this path.

I currently also own a "spare" complete engine for the Rcz/308gti in full fat 270hp spec it's only 25k miles
hence the reason for the question... what else can use as an "upgrade" from it

should I keep it as a spare, ( would no doubt need a new loom and Aftermarket ecu I i ever need to use it ) ...or just recoup some cash ?