So as it turns out, OpenWRT and other manufacturers support USB tethering for a smartphone. This would allow laptops to access the internet via ethernet, and therefore avoiding breaking the rule. Android phones can also be connected this way, but requires an ethernet to USB OTG adapter, and android marshmellow or above.
I have an Essential phone and a Dell XPS15.
I was able to tether my android phone to my laptop using a USB C to USB C cable. My laptop treats it as an ethernet cable, and I just have to indicate in settings on my phone that I am sharing my internet connection over USB, and select the connection in the settings of my laptop.
We used BlueDashPro in our pit to display how our matches went and what the next one was, and we found that just connecting the provided ethernet to what ever needed it worked OK, or we just sucked it up and used the public WiFi. In most cases the WiFi will work fine. A good example was the GVSU competition as last year the WiFi was almost unusable, but it got better this year. Most event venues should have upgraded their WiFi, so tethering or a hotspot shouldn’t be needed.