demon_da the more its being use now as beta, the more we can work on fixing anything that might appear.
Once we are comfortable, we will push it on the standard upgrades repository.
There are people using this in production from several months (before releasing it on the beta channel). The line between stable and beta is a bit blurred. I think Gmail might still be in beta. If you really need to use PJSIP just upgrade issabelPBX from the beta repository, it does work. Be sure you are using at least asterisk 13, that is another requisite... issabelPBX from the beta channel won't upgrade your Asterisk, you must do that separately.