A problem I've seen when people try to seize by force is that anytime a battle gets complicated the MC falls back on making everyone roll to determine what exactly happens exactly every second every time someone twitches their finger. The rules for seizing by force tell you to use it only when there is an opportunity to exchange blows, but the problem is that exchanging blows happens all the goddamn time. There are other things that an MC can do that sort of hint at how to handle these sort of situations, like responding with fuckery and offering opportunities without a cost, but I feel like a more direct rule will help the game flow instead of making it have some epileptic shock every time someone starts fighting.

This is what I use to remind myself not to get stuck like that, tell me what you think.

Streamline the player's moves, but do not disoblige them
When someone seizes by force and decides on an action, he/she does not have to reroll to do generally the same action and the consequences will generally be the same. He/she can continue until he/she decides on different course of action, runs out of ammo, runs out of targets, or is otherwise incapacitated.

A player can be incapacitated by the harm roll, the effects of their total harm, or the actions of another NPC or PC.

IE: Instead of making a player roll each time you want to shoot someone with your shotgun I'll just go off your last roll.

This works when the MC varies his moves. Don't goddamn make every target just shoot at the PC's. Take something from them, separate them, make threat move, or turn their move back on them.

You could even just elide the action entirely to speed things up.

That being said, DO NOT ignore what the player wants and don't skimp on the details. Make the characters as awesome as you know they are, and remember to digress occasionally to add more flavor to the battle.