Funny my old thread got resurrected, I never wouldn't up buying one and started thinking about it again this week.
I didn't buy any because most of the options shown are big and take up a lot of space. Not if I had a house with a garage, but in a studio apartment where most of my tools are in offsite storage, then a 10" x 10" board with different bolts takes up more space than I want to dedicate to checking thread pitches once or twice a year.
I think this was suggested and idk what I was thinking at the time, but it's really small and seems like a good fit for me. Unfortunately I've started an informal Starrett embargo since I dont know which of their tools are being made in China at the moment. I guess I can buy online from a retailer with good free returns (prepaid shipping label) and give it a shot.
Another idea I like, I dont know how good of an idea it is, but I really want to buy a tap and die set, and also a thread cleaner/repair set. I think I can use those as a thread gauge. Use the taps as a gauge for nuts, and use the dies as a gauge for bolts.
It might not be as efficient or pretty as other means, but I literally only find myself needing to do this once or twice per year and I do want both a tap/die and a thread repair set anyway for emergency purposes.