The point of editing the base file is you only do it once for every phone that uses that base file.
I have done some further testing on this and if you downgrade a T46S to the original supported firmware in EPM 1.17 Yealink version 188.8.131.52 this error goes away. So this seems to be an issue with the new EPM 1.18 Yealink version 184.108.40.206 firmware and how it handles speed dial keys. I have also tested newer non supported firmware and the issues is still present. Has anyone heard back from yealink yet on this issue?
Not going to see an update soon. Not really any different than all but nothing getting don in the US around Christmas. Also, I have no idea what part of China. or if they are being impacted by the virus outbreak.