Never do this as this will give less grip at the front and if any tyre is going to lose grip I would rather it was the back.
I run xr4s front and back on one bike and it’s best when the rear wears to stick the front on the back and buy a new one for the front.
I’m in this camp too, always keep the grippier/fresher tyre on the front.
I normally run mismatched anyway with faster rolling tyre on the rear, but if/when I do run same front and rear, I always do the front-> rear, and new on front thing.
Sadly most of my tyres die a horrible carcass shredding death from all the pointy flinty bits long before the tread wears out 🙁