I have not used them, but they look good to me. I'd suggest that going even lower on the gearing is easily possible especially if willing to give up a bit on the top end. I have run setups that had limited range on the top end and found it easy to live with the lack of a big high gear even when there were tailwinds or long downhills. So if you need an even lower granny that might be doable. Personally I find the really low gears some people use excessive and at some point if I need a gear that low I'd just as soon walk. I have never owned a bike with a gear lower than 20 gear inches and doubt I ever will. I am pretty sure you could easily achieve that or even lower with a 1X by using a bit smaller than original front ring.
If I were shopping for a gravel bike I'd consider 1X and I'd be using the gravel bike for touring if I were buying one.
Oh, by the way as far as any problems with the relative chain line being too bad... I noticed that quite a few of the top pros (and I mean the best of the best) were climbing completely cross chained in some recent UCI races on extended climbs. It can't be all that inefficient if they were doing it. Those combinations could be locked out with electronic shifting if they were really bad. So I wouldn't sweat any worries about innefficiencies of 1X
Last edited by staehpj1; 04-02-22 at 02:18 PM.