1x9/10 options

So now I have a bike with 135mm rear spacing I’d like to make it a sweet 1x9/10 flat bar workhorse.
Problem is, no derailleur hanger! Solution I’m assuming is something like this: DMR Chain Tugs & Mech Hanger | Chain Reaction Cycles
Has anyone had any experience? I’m assuming I’d just be running the wheel slammed at the front considering I’d have a derailleur for tension, so why do these have chain tensioners built in? Any other cool fun tips for horizontal dropouts and gears plz holla at me.

hub gear not an option? alfine are 135mm, as are rohloff if you want to get fancy (though not sure if corresponding fancy drops are required).

My Cotic Road Rat* came stock with a similar setup…horizontal dropouts and a removable mech hanger that was held in place by the quick release. The hanger was machined for the frame and I ran it slammed forward. It worked fine although a (very) minor fiddle to get wheel back in, in the event of a puncture. Swapped to ultra-marathons and no more punctures, no more fiddle.

(*sort of regret selling that bike)