Hi,
while i like the design and concept of the mod very much it seems very strong in early game, and I have come up with an idea how to improve this while even also improving the apperance of the mod:

Add tiered Mining buildings:

Tier 1, Mining Hut:

• very rural design
• 2x2 Size
• Can only mine resources without fluid requirement
• Allows a maximum of 5 miner-guys
• slower movementspeed of the employed miners
• slow base mining speed of the employed miners

Tier 2, Mining Encampment:

• 'Like the current version'
• limited to 25(?) miner-guys
• medium movementspeed of the employed miners
• medium base mining speed of the employed miners

Tier 3, Mining Company

• a bigger futuristic building
• Miners do not whack the ground but shoot it with lasers
• also limited to 50(?) miner-guys (based on feasible UPS consumption)
• high movementspeed of the employed miners
• high base mining speed of the employed miners
• possibly Logistics Interface
• if you are bored you could add a slot for transport cars. They would drive to the ore spot and the miners deliver ore to the car instead of walking to the factory if it is nearby

good idea

I was noodling, too, on the idea that you can't "build" miners. You start the game, crash-landed, with game-setting number of crew members. They are precious; you don't want them to die. Later, to replenish or expand your ranks, you need a cloning bio-technology and grow them in vats.

I like the tiered idea - but how about some changes and splitting research -

Basic - doesn't support road network, limited number of drones and maybe other suggestions from above. Doesn't use any power, so available from the start (maybe gfx includes a small solar panel on the top etc), (several?) included in starting equipment

Drones - normal mining drones don't use any power, and can always work without power, but supply 1kw per drone per level (while mining) and they are faster. This increases the mining speed, so almost the same research as currently. The drones can now be built in multiple "speeds" - they will all happily work at a lower speed / with less power, but you need to upgrade the drones to allow them to be faster.
Speed 0 = default, low cost miners (no research needed), faster with power but not required
Speed 1 = previous drone + gears
Speed 2 = previous drone + green circuit
Speed 3 = previous drone + red circuit
Speed 4 = previous drone + lubrication
Speed 5 = previous drone + uranium fuel cell = no longer needs power supplied to the building

Mining buildings - increase range, drone count, and storage
Building 0 = default, supports 5 drones, low range (no research needed), cannot use power
Building 1 = previous building + copper wire (allows connection to the power network)
Building 2 = previous building + road (allows road network connection, use bricks if no roads)
Building 3 = previous building + concrete
Building 4 = previous building + steel

Mining lasers - allow drones to mine at range (under buildings etc)
Lasers 0 = default, can only mine when standing on ore
Lasers 1 = powered drones only, allows mining at range 1 (under walls and 2x2 buildings from the side)
Lasers 2 = as above, but longer range (range 2 for centre of 3x3?)
Lasers 3 = as above, but longer range (range 3 for centre of 4x4?)

Mining base depot - only usable with road network, takes in drones and transport drones, automatically sends mining drones via truck to mines. Allows you to build mines with blueprints and have them auto-populate. Acts as a buffer depot purely for mining drones
Base 1 = research only, so not automatic, ensures there are 10 (?) drones per mine
Base 2-10 = adds a further 10 drones to automatic population for each level
OR
Base 1 = as above, but fills each building to capacity, first come first served
Base 2 = takes input signals of ores, and balances the ratio of miners per signal - higher signal = fewer miners