Nuxwin , I like the idea of a rewrite with Laravel and Vuejs.
I've already asked you if there are mor infos (Laravel rewrite), but if we don't get any informations about the rewrite we can't help you.
How can I help to maintain the new source code?
Shouldn't we discuss if Laravel + Vuejs is the best solution?
What's about the design and principles of the software, before we start coding?
Which modules/functionality should the software contain (API, multiserver, plugin system, etc.)?
There's a lot more which should be discussed in collective. Maybe you do that already but people which are new to this project can't see that and it's very hard to get on. Otherwise this project will stay a one-man-show and the problem that nobody can maintain the main code will persist.