When I first learned about Specialized versions of citizens, I thought it would work something like the following
A specialist citizen would produce a raw point of their specialty item (in the case of Food, at least 2 or 3 Food since they need to feed someone besides themselves) per specialist, and you could only have so many specialists of a particular type, controlled by the number of Districts related to that type. These raw points of production would be BEFORE any % gains were applied as a result of the Districts, Wonders, and Technology and upgrades, etc.
So as the game progressed you could increase your ability to vary how the specialties were assigned, and to WHICH citizen (based on the stats for each citizen) they were assigned to. The stats of each citizen could also affect how much they produced, at least as far as % gains are concerned.
The problem with GC IV 0.4 Alpha/Beta is that Specialist citizens are ONLY giving % gains, they are NOT producing any of the raw production that those % gains are being applied to.
To jump start new worlds, including your Home World (HW), those Worlds whether they are Colonies or Cores, should have some small starting productions of the various types, i.e. Food, raw material, research (or Technology) points, and income (or credits). HWs, special Precursor Worlds and other Rare Worlds, could start off with higher minimums of those various productions.
In GC III population points each produced one Raw Production Point, along with Raw Production (O.5) Points from Asteroid Mines, then the total Raw Production was then modified by the various % gains from Buildings (or Districts), Wonders, etc. Which is what made having a lot of Population Points so valuable in GC III, enough to justify the cost of the support buildings to have large populations on your Worlds.
Wonders and One of per World or One of per Player buildings, would support several of their related specialists, i.e. allow you to assign several citizens to the related specialties. Ordinary Districts would allow you to assign a smaller number of specialists. Upgrading the level of the buildings could allow you to assign more specialists of a type.
The only problem with this approach, is that might cause too much micromanagement in the game. But you could limit the ability of players to change specialties already assigned to citizens, on a per turn basis per World.
For 0.4 GC IV, your population units, i.e. citizens, are not productive enough for you to value them enough to want a lot of them early in the game, or even later in the game. Please make your citizens more productive somehow.
In fact, in GC III, I wanted the Buildings (now called Districts in GC IV) to be more productive, i.e. I wanted the Buildings to produce at least some of the raw points that %gains were applied to. There were very few Buildings, Wonders, etc. in GC III that gave you Raw Points before the % gains.
You have taken GC IV even farther in the WRONG direction, NOW even the population points do not produce the Raw points before the % gains are applied. Which makes it even harder to actually produce anything in the game. In GC IV population points are a lot less valuable than they were in GC 3.
At the moment their greatest value is in building Colony Ships, Construction Ships (and therefore Star Bases), and for Troop Transports to invade with, along with defending against invasions. For most other purposes, the basic stats of the World matter a lot more than size of the population on it.
PLEASE, at least allow specialized citizens to produce raw points of their specialty before the % gains are applied. Maybe basic citizens with no specialty could produce their skill level/10 of something, i.e. a 5 Intelligence skill citizen would produce 0.5 research, and a 0.5 skill in Social would produce 0.5 in production for Social or Ship building, etc.
While specialized citizens would produce even more of their specialty (perhaps twice, i.e. a 0.5 skill would produce 1.0 or thrice, i.e. 1.5) but less (or nothing) of the other items.
That is what I would want and expect in GC IV.
To me, citizens in GC IV are just not productive enough for me to want to pay the expenses of the buildings needed to support large populations on a World, no matter how many tiles it has to use.