I like the idea of pressure fermenting, that sounds good. My FV is a SS Brew Tech Chronical. It’s great, but isn’t rated for more than a couple of PSI. I also don’t like to cold crash in my FV as the change in temperature causes sanitiser to get sucked back up the blow off tube (I don’t have enough headspace in my chamber for an airlock).
I have a modified corney I use as a bright beer tank, I’m considering one day transferring the beer in there when fermentation slows down and using a spunding valve. I hear beer carbonated by its own fermentation can have smaller bubbles and smoother carbonation.
Still not an ideal solution, but I don’t think now is the time to be buying a unitank!