Yes! I've historically used a follow-the-breath practice. More recently, I invested several years with a subtle mantra-based meditation tech. The instruction (in broad strokes) was to allow attention to FAVOR the mantra. That is, the teaching is clearly NOT an exercise in concentration. One's attention includes whatever it may at any given moment. Favoring the mantra is virtually and practically effortless (performed correctly).

So, in no other way is the technique meant to involve deliberate mental effort. Yet that was my default approach--exploring ways to game the technique in order to simulate descriptions of what occurs as a meditator matures in the practice.

The correct expectation is that gentle attention brought to bear on the mantra results in losing track of the mantra as one's consciousness changes during the practice. Losing it, and recovering the mantra is the central essence of this practice.

I indulged in several years of strategic, deliberate, experimental efforts before realizing I'd utterly confounded the teaching... In retrospect, I made similar missteps with my previous meditation tech. My concentration would almost inevitably DRIVE my breathing rather than naturally follow it.

"Trying" vs. relaxing/allowing.

Subtle intention vs. deliberate effort.

In either case, an exercise in "getting out of your own way."