Glad you can find use for it. Like I said it's not my idea, I just got it from a YouTube video. I've been trying to find grating like that for a long time.
I got another tabletop gaming staple today, that will work great for 3.75. Tube blocks. They're plastic tubes made for toddlers. You can connect them and make plumbing, apparently kids like it. They have a few different connectors, straight, elbow, X, and T, along with horns and wheels. The set I got is 136 pcs for $20.
https://www.amazon.com/dp/B0725ZLZP2/ref=cm_sw_r_cp_apa_i_75hiFbRMS2E35Painted up they would be really cool in a Star Wars Dio or an industrial scene. I was playing with them and the only problem is, the straight pipes have male and female connectors, and sometimes I can't get them to connect the way I'd like. I could always cut the female end off the straight pipe, or use PVC pipe. The Outside diameter of the male ends are 2 cm, (metric of course) so it'll be difficult to find a .787" pipe, but I'm sure 3/4" pipe will work. I'll make something with them soon to give an example.