At the point where I am using DT shifters, the first thing I prefer to do is eliminate any 1-tooth steps in the cassette's gearing.
This makes for fewer shifts and also prevents the severe cross-chaining needed to access lower gears while staying in the big ring.
So this allows for infrequent need of any front shifts.

With a 10-speed mtb cassette, just as with Shimano's latest and largest road cassette (their 11-34t 11s), there are no 1-tooth gear changes.
And with such a large range of ratios, it would make sense to just toss away the 11t cog from any 10s cassette so it might fit on a 7s freehub and 126mm axle spacing if that happens to be part of the existing bike's configuration.

I ride old bikes with DT or stem/headset-mounted levers and really haven't noticed much of a performance liability (even in sporting use) from use of cog ratios as widely spaced as 13-15-17-20-24t for the 1st four positions of a 5, 6 or 7-speed freewheel. But with 9 or 10 cogs this ratio spacing can easily get you up to a 34 or 36t low gear, with the small ring then reserved only for bail-outs. BTW, the 10-speed levers will index a large 10s cassette using any 9-speed Shimano MTB derailer.