I've been using the middle ring and the entire cassette (FW) for more than 40 years. The cross-train gods haven't struck me down yet. I try to stay out of the bottom two cogs on the big ring and small ring is limited to whatever cross-over I can achieve without too much chain rub on the larger rings. (Pinned middle and large rings are a curse here.)

One thing I do is try to always use middle chainrings big enough that I am not using very small cogs on normal flat ground riding or the big ring on big cogs. 42 tooth middle ring means I am riding 15 and 17 tooth cogs a lot; nicely located near the middle of my cassettes. (I spent one year a dozen years ago on a 53-39 racing crankset. Hated it. The 39 was too low to be a good flat ground ring and not low enough to be a good climbing ring. Spent a lot
of time in cross-overs and did a lot of double shifts. Compact gearing strikes me as a step worse except that you can go uphill.)

Ben