A gutter extension would not make this meet code. Any more than 30 conductors in a cross section, and you have to derate the conductors. 31 conductors will get you 40%. An extension would be like putting a band-aid on a shotgun wound.
Some of you may know that I just started at a new company... Who from outward additute, take pride in thier work. I haven't done any rough with them yet, just trim and changes on current projects, which all seem to be a little like this. Fast and sloppy.
When I mention things like cable supports, fill, derating, how many conductors wirenuts are rated for... I get a blank stare, and comments like "What do mean, it's fine?" So am I just a neurotic code geek, or a premidanna? FYI that thing is just as hard to work in, as it is to look at!
Mark Heller "Well - I oughta....." -Jackie Gleason
I know the fight you are going through e57, it’s tough to convince people that there should be a certain level of professionalism in their work.
While I think the other picture I linked to is a bit too much, it does allow some points to be made.
Ask your guys how long it would take to troubleshoot a problem in each picture. If they don't say their work would take 4-10x longer gently smack them upside the head
Another point that is often harder to get across to the guys in the trenches is the business perspective. The owner who has a friend down the street that is building his house, which electrician would he recommend? Or which picture would you put on your website/flyer to promote your work?
Like I said, I feel your pain. The attitude, it works and it was fast to install is a hard one to fight.
I suspect that on the issue of derating, there really is not a problem. Looking at the DIN rail terminal strips, these are probably lighting and control circuits operated at well below their ampacity. There is almost certainly a violation of the code in terms of cross section fill and derating, but IMHO there is probably not a significant conductor heating issue here.
On the shear messiness and difficulty of debugging....arrrrrrgh.
This particular issue has been discussed several times, usually with respect to a trough feeding a bunch of emt and several panels. There might be hundereds of conductors in the trough. With any complex system, you either have to spend lots of time making sure that all of your breakers are in order relative to your incoming emt, or you have to have some sort of 'crossbar' where you can match the innies and the outies.
I've though that this presents a market for some sort of 'matrix trough'. Imagine a trough say 24" high by as long as necessary, with insulating pillars or bridle rings, say on 2" centers. Each row or column would define a 'wireway' that would be tested and _listed_ as having a capacity for (say) 20 current carrying conductors without derating. (No, I've not done the physics, and don't know what the capacity would be.) Wires would be separated throughout the entire 'trough', and so easy to get at, heat could be dissipated, etc. Complete circuits would be required to sit in the same 'wireway', to reduce loop area, and there would probably need to be some limits on the number of splices.
Another approach (this one suggested by the picture of the panel with the neatly bundled wires) is some sort of 'stacker' where individual conductors are held in neat _separated_ rows, where each conductor can be easily found and traced.