>>Hard to believe nobody has compared Psvane 845-HIFI series tubes (not 845T) to Shuguang 845B since Psvane 845-HIFI have been on the market for a while. <<
Frankly, with the Psvane 845-T having been disappointing, there isn't a lot of incentive to bother with the more prosaic 845HiFi when the B tube is so reliable, cheap and good. It's easy enough to buy a pair of 845HIFI tubes online fairly cheaply, so if you're that curious, have a go.
Phil