Edit: after further thought, I feel like just trying someone else's setup with 8.5 Slappy's/T2s on a similar enough deck size would probably be enough to scratch that itch. Though I don't know anyone with them or I probably would have already. Trucks are definitely a longer commitment and I don't wanna buy something I might not get the use out of. Maybe once my Indys are cooked I would consider trying something different, but I'm not sure I'd really wanna make that big of a change for so long.
This line of thought is why I have amassed so many completes and setups, so given the place I have is a skatepark / shop combination, it really only works in that environment, for a "try before you buy" type deal, which has helped so many people to, as you say scratch that itch, which I think would have a fifty / fifty result, eg some people really like the setup or combination of certain parts, while others said they are happy they never actually bought all that.
Of course, being a "not for profit" type setup, I am not worried about trying to make as many sales as I can, so it is a different setup right from the start there, but just the fact that I do try to keep as much second hand gear as I can, for people to try as a complete, or even swap onto their own setup to try, it can make things a whole lot easier for someone to figure out if they really do want those new trucks, or wheels or whatever else.
It has also been a lot of fun messing round with things too, as I used to have my boards, DLX 8.12 with Indy 139s / 144s, Spitfire wheels, just have the same thing over and over, cause that was all I needed, same when I switched up to 8.5 or 8.38 boards, still Indy 149s, still Spitfires, etc. Even my "big board" was always just the same on a larger scale, BBS wood, Indy standard 159s, Spitfire wheels and on and on...
These days I have a lot more stuff, from both my own interest in trying things, as well as trade ins, so any number of different woodshop decks, a good number of different trucks - Indy, Ace, Thunder, Venture, Slappy and more, pretty much every size, or type, eg cast and forged baseplates, regular, hollow or ti axles, then almost every brand of wheel too, or at least pretty much every option in wheel manufacturing, Spitfire, Bones, Aend, Creative, etc.
The best thing is where we are, there are a good number of different surfaces, so there is bitumen / asphalt carpark, rougher concrete, smooth concrete, painted concrete bowl, raw ply wood surface, skatelite surface, other composite ramp surface, etc. That way, testing whatever wheel options can be good to see what the wheels feel like on every surface too, some of which perform really well, others best on this but bad on that, so I guess that has helped me to be somewhat of a "know it all skate shop guy" when helping anyone, in person, online or where ever really.
To say I have been pleasantly surprised by some products is an understatement, eg the new Thunder T-II trucks are going so well right now for me, both 149s and 151s on their relative boards, or even tinkering with certain things I just never would have thought I could make work, like Venture trucks being able to turn almost as much as Indy, or reshaping wheels or decks or any other number of things too. Almost too much to list, but it could definitely be Gear Madness, if I let it.
I still have what I know works best for me and that's quite ok, so it is interesting to get new and different things, but I am not about to go out and buy one of every new thing that is out there, just the things I think would be good to have, to try, then to keep for people to try too, if that all makes sense.