Yup
Your cockroach and king roach vessels seemed straight awful at first, but after around 3 days of constant meddling and fixing different layouts (and writing them down on a google doc - seriously you weren't kidding when you said a lot of work) I've made them into stupidly efficient combat vessels (that I can only put more weapons on as they die).
I reverted the change I did to flux dissipation to the Junk after seeing this, while I still believe the flux dissipation could be raised by a 100 for less storage space: I plan to try harder to make it combat effective. It's all around nature is quite fitting for my current mining/bounty fleet, acting as (ironically) a much better fleet anchor than the Bastillon and Scarecrow (lol) due to it's armament options alone. The cockroach being 8 deployment to the king roach 26 seems like such a huge margin though, I feel the king roach could be lowered to 20-23 range instead because it is still a slow flying hunk of metal (that said I'm almost certainly biased because nothing beats tanking an Onslaught in the face while pumping lead at the same time).
The smaller ships (particularly the 1 deployment cost vessels up to the glimmer) are relatively average with clear drawbacks. I've had quite a lot of fun turning your pickets into effective frigate swarmers, their stupidly high fuel cost is a bit painful though (and honestly kinda fair given their strength en masse). Don't even get me started on the sentry, I was just being really unlucky with getting the seth drone fabricators which are incredibly cheap and also incredibly weak. However they do have unlimited ammo and oh look the sentry has 'fast reload' as an ability ... I wonder....
Nothing beats having 20 deployment cost worth of rapid firing seth drones slowly inching their way towards the enemy. Effectively turning into a sorta of mega forcefield wall with the drones able to soak up damage. Granted I had to pay enough to fuel a fleet to the next sector and still suffer losses which I'am not comfortable at losing (30 OP can't fit reinforced bulkheads unfortunately). It just so happens that this seth drone wall is also perfect for picket, cockroachs and king roaches to get withing range. Though this tactic is nowehere near your intended gameplay of the mod due to the exorbitant cost in fuel and supplies to even use such a fleet.
On that note I've been trying to spec an army of only junker ships against Soren's Dassault Midorayan Engineering fleet and boy has it been a tough fight, immensely fun though (my ships are effectively zombies 6th gen now, they blow up in seconds and blow things up in seconds - provided they reach the target).
Currently trying to effectively outfit the non-carrier salvaged remnant/domain era ships to be support craft but so far been quite troublesome, they aren't as upfront and bashy as the cockroach and king roach hulls (and I've sorta grown accustomed to having no shields). The Clyde Rapidfire cannon seems a bit on the weak side personally but as all things, I'm gonna give it a few days before I make any real remarks, the same goes with a lot of the other non mining weapons you included. The Desolator cannon is straight out of hell in power and coolness factor though, props to you. That thing is the most fun I've had in ages (nothing beats burning a frigate in 2 seconds while it's shields are down which Mikoyan kinda makes a fuss about lol).
Overall this 3 days have just been a really fun (sometimes infuriating) time.
EDIT: I noticed your MARK IV cannon states that investment into magazine expansion helps it, does this mean the hull mod? and if so, mind putting in a small tooltip to say that?