These default settings have existed for years this way and worked for hundreds of thousands of people, except for you. When they don’t work for you then you automatically jump to the conclusion of “so Sangoma support can make some $$$”. The community at large actually flagged your post because it was concerning.
Here are the settings you are referencing
And here are the defaults from Asterisk themselves. They are the exact same. Which is why we set them this way. (https://github.com/asterisk/asterisk/blob/master/configs/samples/sip.conf.sample#L285)
The descriptions we provided are also the same descriptions that are in the sample files.
I shouldn’t have had to even explain this.