Substitution rule is an example of unintended consequences. And, it's what we do as coaches.
Example in another sport,
Fastpitch softball was plagued with batter/runner taking off to first base on an uncaught third strike, when there was less than two outs and a runner on first. At the lower age levels, it caused chaos, and muddied things up occasionally at the 18-unders as well.
Added the caveat that if a defensive team threw the ball to first, the runner headed to second had to come back. We instructed our catchers on passed ball-or wild pitch-third strikes to fire the ball to first. Took advantage of a rule. It's what we do.
Couple of years of that, governing body changed things back. Know your situation is back in force.
How they are going to solve the substitution rule currently in place is beyond me. There are rules, like 12 in the huddle, that I don't profess to know. Used to know the NFL/NCAA/NFHS rule books, not now. I'm up to snuff when high school softball rolls around and that's it.