The other thing is that if you're making five or six cups, there's a fair amount of volume of liquid, so it won't cool as quickly.
While @buellbrewer has proper insulated presses, a 'normal' borosilicate glass press will keep the coffee pretty hot for those minutes, especially if you preheat...
Update:
I've been playing around with a lot of different 22LR brands, and the results were pretty impressive across the board - much better groups than I get with my trusty old 10/22. So much better, that I think I can justify some nicer glass (or at least better magnification) than the Vortex...
We get ours from these guys.
Good selection but not cheap. But then, life's too short to drink crappy, cheap coffee.
https://groundsandhoundscoffee.com/
100% on using either the low tech filter cone or french press method for making good, flavorful coffee easily.
I think it's actually a lot more straightforward than that, unless you think the ATF is really "out to target you" personally. In which case they have a lot of other ways to eff you up.
If you establish a pattern of behavior, buying items and then selling them unfired or slightly fired, over a...
I don't think you're at any significant risk. You've owned a selection of different firearms over the course of a couple of decades, you're selling them off and - most importantly - you're not replacing them with 'new stock' that you're turning over, fired or unfired.
If a vendor doesn't take credit cards, just walk away. For funsies, you can verify they're a scam if they also sell guns, but just putting one in your shopping cart and ALMOST completing the purchase. They won't ask who your FFL is.
Other indication - no way of getting in contact with them, and...
You've got some choices, some of them quite good.
If you're interested in purely velocity at the muzzle, some of the old kinds of chronos work pretty well, as does the Magnetospeed (as long as you don't shoot the bayonet, no matter how 'lightly'). The Magnetospeed does seem to be very accurate...