Voltage have some problems for managing feedback routing, eg, route a delay signal out to a reverb in and the reverb out to the delay in.
A momentary solution :
Insert a limiter module and a distortion module in the feedback path, with that, you can manage the feedback signal more easily without overslaming the output and find the sweet spot.
I don't know how softube manage it, but it do it well.
If you find some others solutions, we could speak about it in this thread.