Its a bit dated, but I could follow what was going on and its still relevant afaict. I understand that with running Transmission over OpenVPN you need to compensate for the changing ip-address of OpenVPN. However the one bit that was odd to me was: if the VPN is stopped for some reason the bind-address is set back to 127.0.0.1.
I do now there is a setting available in the config called mem_percentage which is not visible in luci. It was set to 50 and 8GB*0,5=4GB. Idk what a good percentage is? but ill set it to 10 for now.