I completely gave up on the wrist oHR of my 935 months ago as the results were completely unpredictable and generally poor but could work for slow steady runs...The other day I forgot my strap and couldn't believe how terrible the oHR was, completely ridiculous overstated values for a slow steady run. I stopped, readjusted, moved up the watch, etc...no change. I just turned it off in the end.
Anyway it struck me that when I first got the FR935 the oHR after having the FR235 for a year it seemed really good...as the FR235 was when I first got it and then we thought here that FW updates had messed it up...and come to think of it, same for my wife's VAHR that was really good for HR at first and is now totally useless.
So yes, you'd think that the main advantage of oHR vs straps is that time should have little effect on it, but maybe not, anyone else noticed that with several oHR equipped watches ?
