I feel the VHR VQ's sweet spot for power and reliability is around 750whp to 800whp, that's after being full built as well.
If you want more and want to be reliable I think a VR38 swap is the way to go or obviously a nasty boosted v8.
If I keep the Z and don't go to a 2023 Supra with a 6MT when they release, the VR38 swap will probably be the route I'll take.
Last I heard used VR38's are only around $10k now (correct me if wrong) and even in stock form the VR38 can take more power than even a built VQ.
If and when I start chasing big power for the Z, the VR would be my goto.