@archiel, this script uses the same Asuswrt-Merlin behavior when you enable guest networks 1 (2.4Ghz or 5Ghz) without intranet access, for all other guest networks, so it provides better isolation than the default guest options. I only have one RT-AX86U, and I wanted to isolate my lan network, from well-known devices (family and friends) and from IoT. So I've built this script.
Frist I need to stable the script, and try it with other Asuswrt-Merlin devices, than I'll try to add more Asuswrt-Merlin addons like diversion and skynet. Logically there isn't any confit with those addons, but I need to try to tell you for sure.