That’s a great valve setup. Just be careful in freezing weather to keep the hose off it in cold weather and don’t use one of those quick connects with a check valve built in for the hose. If you leave water trapped in the outer parts of the valve they will freeze and split.
I did mine as I did because I didn’t want anyone getting scalded by turning on the hot only as when you attach a shower head it isn’t a non-scald mixer like in a normal shower. I just set mine in the house to be tepid and it can’t get any hotter. Good enough for rinsing off a swim suit.