Alps Pacino
this isnt a dig back but most people know what these engines are capable of.
I mean, a good strong CVH turbo is good for somewhere near 300Bhp with the correct management and turbo selection. How long it lasts is another thing

I know of standard bottom ends having 16psi of thrash for 000s of miles.
To get back to topic, a good well maintained VAG 1.8T with 100k + should be safe for 200Bhp IMO.
I was quoting what a certain so called Tuner preached to me many moons ago.
p.s. BTW your engine route conversion sounds

Good luck