Unfortunately, the above instructions didn't work, and was actually worse.
When I did the above, Avplan did not connect to the Skyecho, but in the tablet settings it showed the SE connected. So I had no traffic info and no internet access.
I have found a workaround though.
Leaving the IP set to DHCP, the SE connects and shows ADSB traffic on avplan.
Then in the tablet settings, I can select which apps only use mobile data, not wifi. Setting Avplan to mobile data only and I get both ADBS and Avplan traffic and internet access through the mobile data.
It means having to manually set this each flight and reset it to wifi when I get home, not ideal, but it’s manageable.
Another drawback of going Android over Apple.
But, I did 4 hours the other day, with no overheating, so 🙄