I can’t speak for others, but I’ve always done a lot of production, and I feel like doing cost/benefit analysis is kind of a central part of industrial gameplay. I would definitely not assume ME 10 is worthwhile, at least on any blueprint with a large research multiplier. Subcap modules and the like, sure, I plug those in for 10/20 just because they’re there and I have slots free.
However, I’ve been doing industry since back when there was no hard ceiling on ME/TE (PE, then) at all - you could research them to arbitrary levels, but there were diminishing returns. Under that model, you sort of had to figure out where you were going to stop because, “ooooo, if I go from ME 60-65, I can save 3 more tritanium on my capital armor plates!” So, that may influence my habits somewhat.
I’ve also built my own production calculators and spreadsheets over the years (which I don’t think is uncommon behavior among “scale” industrial players) which kind of forces some awareness of how the math actually works (such as the single quantity minimum).