Gorgon Zee
Hero
Gumshoe RPG has the Preparedness skill that helps minimize planning and maximize execution. I'm fuzzy on the details though. I don't remember if it just gives you access to equipment in hindsight or if it gives you more freedom on what you planned. Dusk City Outlaws and I think Blades in the Dark have a similar planning mechanic to address this issue.
It gives you access to equipment; if you have 8 points in it, it also allows you to retroactively ‘have planned’ something.
So, typically, when I run a scene, I’ll establish base materials as the GM, ask if anyone has anything special they want to bring, and then go. It makes scenes fats when necessary, but still allows plannig if there might be a special need.
So, for example, raid on a ski lodge (a vampirized Putin’s mistress was the target). I said something like “you have all your usual combat gear to hand, but not a lot of time to get ready, so light body armor only. Everyone has their usual bag of tricks (whatever is needed to do their skills). Anything else you want to bring along?” The players recalled rumors of werewolves, which were unusual in my game, so they stated they wanted to bring silver bullets and the silvered swordcane (that saved a preparedness roll later).
Once inside they found well defended areas, so they wanted to use some heat detection tech. That required a preparedness check as it’s not usual stuff. Much later they were being swarmed by werewolves, so a player with 12 points of preparedness spent 5 to retroactively booby trap an exterior door.
That’s a typical way it plays out. I would absolutely recommend you add the skill to any GUMSHOE system. It makes technical preparation so much nicer. Players just concentetrate on the really important things and don’t sweat the details.