Very cool concept and interesting mechanics, but as it stands now, this mod is highly unbalanced and has some unfun interactions that make the game drag out for unnecessarily long.
Lets start with faulty interactions:
Why should you fight an easy fight 4 times over? The retreat mechanic is cool, but it should be made so that you cannot deploy these ships below 30 CR, cause fighting against 10 phase ships with critical malfunctions is boring and a pointless waste of time. They literally die themselves from the malfunctions if you just wait. But in some cases, a few of these 0 CR ships still manage to retreat manually. And what does that mean? Yes, another pointless fight. Then they think that these few malfunctioning battleships + 10 freighters is a good composition for battle and so instead of retreating for real, they will force another fight. Idk if this faction has a reduced chance for escape from potential combat or what, but they just seem ridiculous:
Another thing is the balancing issue. Some ships when in player hands are way too overpowered. The biggest offender for me is the Kelpie class cruiser. When I pilot it, I can solo 10 - 15 non-omni shield capitals or 5 - 10 omni shield high-tech capitals. And all that for 25 deployment points. The last 3 reports from "Starship legends mod" show that I do around 3000% of my hull as damage that's just a little bit shy of 300000 dmg per combat.
Admittedly, I have almost all combat traits and that phase ship trait, also, I have all S-mods, but even without the level (you do need field modulation for phase cooldown) and S-mods you can achieve superb results. All you need is 4-6 anti-matter blasters max flux capacitors (more capacity = better results) and a phase anchor, you employ a strike and run tactic, but don't get confused, you shouldn't run after each volley, you should just keep phasing and blasting, because that's where the phase anchor comes to play, it makes the phase activation cost 0 and weapons recharge at 2x speed, so in turn antimatter blasters recharge over 5 seconds. That means that while phased, you can just dissipate the soft flux from the blasters, while only 1.5k hard flux comes from phase upkeep (300 per/s by default). At 0 vents you dissipate 800 per sec by default, so 4000 flux per 5 sec, then phase anchor DOUBLES that dissipation to 8000. In turn you can basically dump 8000 flux worth of ordinance for only 1.5k hard flux, and that is when you have 0 vents, 1.5k per shot per blaster means you can run ~5 blasters with 0 vents.
I personally run 4 blasters with extended mags and some other strike weapons. Other weapons don't have an ammo limitation so I can cause mayhem even after I run out of blaster ammo. One of those ways to cause mayhem, or more specific, reduce the amount of mayhem that falls upon your ships, is using that OP system ability that makes you invincible. You can just keep in front of high flux friendly ship and with efficient phasing block almost everything, system expertise skill helps a lot, as you don't need to stay phased for that long to recharge the ability. By the time you have lots of hard flux, the ship you were protecting most likely cooled off and you can just vent behind it and continue near invincibility play.
Suggestions on how to balance the Kelpie class:
First approach: Simply make it that high flux penalty also applies to ship speed (To a min of 50% speed at 75% flux), and not only to time dealation increase multiplier. Because as of right now, you can traverse half of the map in moments and that speed penalty would deter staying surrounded by enemies (because right now there is close to no risk even if 10 ships are firing upon you). I don't think that this is enough, so you should combine it with a lesser second approach (instead of 75% - 125% increase, change it to ~40%).
Or instead of second approach, combine it with third.
Second approach: Remove phase activation cost, but increase phase cost per second (I feel like increase by 75% - 125% should be right, as you get some free extra time by not paying the activation (or at least the AI will get it for free cause phase anchor is still good for 2x flux dissipation and weapon cooldown)). This shouldn't nerf AI that doesn't use phase anchor, but will be a significant nerf to player pilot that can abuse Phase anchor.
Third approach: Make phase anchor incompatible with ICS framework. Simple. Nerfs only player.
A must do change is for the System ability. It shouldn't allow for no consequences tanking. Make it so you still repair armor instead of taking damage, but 15 % of that damage goes to hull (Idk about the values of this one, as I usually just kill the enemies instead of infinite tank)
You could also make the AI use some heavy strike weaponry, cause the current loadouts for the AI on this ship are not great, I noticed that they use lots of fast firing weapons or beams that do not play into this ships strengths at all.
But who am I to speak, I did not put any work into this mod, so you can chose whatever you see fit. I wrote this long comment because I respect your efforts and wish to see them shine. Good luck in Your future endeavors.