how about just ask him if there is a time limit on taking a shot.. fair enough to come to a resolution, right?
if the time limit is 3 minutes and that's what he's taking then you have to suck it up because he's playing by the rules, you just dot like the set rule and feel it should be shorter then,
If you are just playing one on one you might say Ill only play you in you reduce the time to 1 minute, or similar..
If that's a rule set by the league or tournament or "house" then it's that "power" you should argue with, as it's not his fault, It's yours and you are just frustrated by the rules.
If he doesn't know then its a chance to come to a realistic number. ask him what the penalty is if he runs over.. ball in hand? end of game?
I think the issue is you aren't being direct enough and that's the way out, to come to an understanding.. This doesn't need to mean an argument, so I'd try to not phrase it as one.. Tell him directly, say "the wait time between shots is frustrating me"..
If you want use sarcasm wait 1 minute , or whatever is reasonable then say "would you like more time? " continue that until you have a proper discussion.
That tactic will be distracting.
I think the direct approach is likely to actually solve the issue.. Once you bring the issue to light in a clear way, he may help you find common ground rather than arguing the point.
If you can get his buy-in on a resolution, that's more helpful than a polarized or defensive type of discussion.
The direct approach is how I'd handle it if it bothered me enough. fair enough to say you don't want to leave it unsaid until you are in melt down mode about it all, so you decided youd like to have a respectful and direct conversation..
any gentleman with dignity or respect will reply that they were not aware their slowness was bothiering you in that way or to that extent, and then look for common ground.. if the guy is a jerk and gives you childish feedback like bickering,, then you tried and then you can then just be rude back and at least you cna say you actually tried to take the high road as a first step.
one way that can be both polite and kind is to say you need to talk to him about something you feel is important , and go sit down with him. treat him to a beverage or whatever.. what that does is takes the other distractions away and allows a logical eye to eye conversation to happen rather than the subject being deferred by continuing play. the fact that you took him aside to talk means it bothered you enough to take the time for a decent and non- insulting gentleman's discussion.. If it blows up and you need to talk to some "manager" then at least you cna say with clarity, I tried to sit him down and have a clear and proper dicussion before thinigs got so out of hand.. That would generally be respected and thats why I wouldn't have the conversation at the pool table..
i remember watching a snooker pro on youtube, hes somewhat of a snooker authority. He pointed out that if you have a conflict, stop game play, have that discussion , find a resolution , then continue the game, I think that's sound advice. It beats playing with a grudge on your shoulders.