I have the VA one way valve in mine now, seems to work ok and I run around 205* but I did not do any comparison to a crossover, and I have not made it out of my driveway yet. My factory equipped LS engine came with a crossover so apparently GM thought it was necessary. There is a couple folks that did extensive testing to show it does make a difference if your actually testing and measuring temps.
I think unless your at max AC or completely turned off in the VA setup, the HCV will always be open somewhat anyway and be much less noticeable of seeing any changes in temp.
I have ordered a bypass already and have my system drained anyway doing a cam swap, so I will just change it.
I also found this part interesting
https://www.lojkits.com/products/ls-...r-bypass-block. When your one way valve is closed it just redirects through the H-channel. Should work similar to the double "T" mentioned before.