What's the issue with the deb packages, what is wrong with them, where & how do they need improving ?
Building the from source is a simple process. It doesn't give you an insight into how a package works.
They are used by hundreds of users with no issues.
I make deb packages from source for ease of installation, rather than having A RIP installation, plus the machine I build on is way way faster at compiling. If I want to know how Linuxcnc works, I use it what is was intended for, controlling a cnc machine, read the docs and have a look at the source.
Running a machine & reading docs will give you the best insight.
I could teach my mother, who is in her 60's how to compile from source, the only thing she will learn from that is how to build from source, not any insight into how it works.
If you really don't like deb packages, which seems strange, you can always go this way,
www.linuxfromscratch.org/
, which I did once build a working Linuxcnc setup from, but when all is said & done, whilst it is fun, there really is no advantage.
After coming from Slackware & Redhat background, I really appreciate how easy it is to install software via deb packages.
If you really really want to cause yourself mental harm and waste hours chasing libraries and building from source, with no clear list of libraries and dependencies, install Slackware 14.2 and then install gitlab.