Hi. Bought your alpha (12) and put around 20 hours into it.
Overall, great potential. Keep it up!

A few points:
*) Multi-ship fleets are a chore. There some helping automation going on with shuttles carrying missing materials, but not nearly enough to enjoy a fleet.
A lot of this comes down to shuttles themselves (see below). I think more automation is required. By looking at the ship systems it's easy to deduce what resources it will definitely consume in the near future, and carry those in advance.
Right now it would be really great to have an option not to deploy every single vessel every time I enter the system. The increase in fleet firepower does not compensate the increase in workload. If there is no fight, I'd rather not deal with additional ships.

*) Shuttles are annoying in many aspects. They are extremely slow. To supply a second ship while carrying usual duties I went from one shuttle bay to.. four. And it is still barely tolerable. It would make some sense for them to be this slow, if they could be targeted and shot down, but they are invincible.
Which brings us to the next point:

*) Boardings. Comparatively to the level of automation of the rest of the game, these are a chore. So much so, that after awhile I don't want to do them anymore. Just can't bring myself looking into another derelict. I think clicking port/breach on the ship should give you an option to assemble, launch and deliver a boarding party and leave user with just the fun part.
Boardings are unopposed. If one wants to board, there is nothing for the target to do about that. I would expect capital ship to be able to damage or kill a puny shuttle, which will gut it if unopposed. It would also give a lot more sense to those dialog tricks to sneak your team into the ship. Right now one can break into anything with zero effort.

*) Capital ship weapons are useless outside of initial ship-to-ship exchange.
They can't kill a shuttle. They can't kill a single crew member, can't perform as a boarding support artillery. You don't need them to breach, since boardings have no obstacles whatsoever: airlocks of hostile ships pose no challenge. Also, there should be a quick button to select all weapons on the fleet and fire at something. That's the exact use-case almost 100% of the time.

*) Block supply restrictions between systems is too harsh. Right now in any given star system some building block will always be at zero (or 1-2) supply. I get that this is an encouragement to produce (and/or hoard), but I expect boarding advanced enough tin cans should give me plenty of required material.
As of now disassembling other ships is not worth the time spent.

Overall, I think base one-ship basic gameplay and management is pretty solid. I was enjoying the building and designing my ship, redesigning it defensively as I've gained more game experience. Looking how my crew goes about their business.

Stuff outside of this microcosm was not as great. Boardings turned into boredom especially quickly. After you've assembled your crew, not much to gain by successful boarding. Straightforward laborious mechanic brought no satisfaction.

The game also forces me into a very generic one-ship-to-rule-them-all design. I seem to have to have every producing facility in the world, even if I'm willing to build a more specialized tight ship and ask for stuff nicely (boarding).
There is also a third established route missing from the game for enabling specialized designs to survive: quests and rewards.

Core game engine is great BTW. Even huge ships were running very smoothly on Linux Intel GPU laptop with iGPU. No crashes either.
Good job!