I’ve heard this strategy, but never seen it implemented. I’m not sure I would consider it abuse of a rule, but you do bring up a good point that there must be some limit to where he can go. There could be an argument for calling him out for making a travesty of the game?
As for defending it, I would step off, throw it to my second baseman standing in the actual ”baseline” and have him work backwards towards the runner with ball ready and positioned to throw to home at any point. Once 2nd baseman heads towards him, he can’t back up any further and at some point will be “trapped” into heading to a base.
As for what I think of it, I try not to judge other coaches for how they coach their team unless I have an ethical issue with what he is doing. Doing gimmicky or different stuff may be his way to break up the monotony of practice or long season. I run trick plays in football not just trying to get a cheap TD, but to keep up morale.