@patrikg: I am glad that you agree with the idea to combine tcz into one big for huge tcz+deps (like Xorg server)
Regarding multi-core CPU: It is a waste of (expensive) electricity to have 100 cores and NOT use all together for 1 second, instead of one core for 100 seconds (the 99 cores just sleeping). But it is a say, like
"double of nothing is nothing!".
Because I am not a programmer/developer, for me the Pareto principle apply, 80% efficiency with 20% work. So spending (2-3 hours ) time to "improve" tce-load, just to recover them in 2-3 years, is not worth for my time. ex: 365 days/year x 3 years / (10 sec / 60 sec/min / 60 min /hour => 3.04 hours.
PS: the "deep" tree can be seen from TC appls, or from /tmp/tcload/extensions.