I've been editing the uboats *.zon files for some time now. I think I started this about when the first GW mod came out. I always set the HP at 2000. This is somewhat like Thomsens mod.
I did this because in stock and in gwx the death screen shows to often and that is really annoying.
With higher HP you have lot's more 'Das Boot' moments
So I would say, download the mod and give it a try.
p.s. Don't forget to Backup your uboats *.zon files first.