Below are a couple of issues I'm proposing a solution for:
1. Tech mining industry isn't widely used, an industry slot is valuable, and the rewards aren't great.
2. To use tech mining you need to found a colony, build a spaceport, and potentially defend it.
3. There isn't much incentive for expanding outside of 1-2 systems that have the resources you need or founding colonies far away from the core due to the accessibility penalty.
Potential Solution:
An outpost option is added in addition to "colonize" option for planets with ruins. This option requires $100k, 100 personnel, 200 supplies, 50 machinery to setup.
It sets up a an "outpost" with essentially the same GUI as a colony which costs around $1000 per month (dependent upon ruin type, and hazard rating) to sustain, has a "landing pad" instead of a spaceport, and only has the tech mining building on it. Tech mining can also be built on regular colonies but is no longer an industry.
This will let players essentially build outposts around the sector and expand. You can dock your ship at the colony but you cannot outfit your ship differently than you would normally in space (without a penalty). The outpost has no tradeable goods except for that which the tech mining industry creates which you can pick up. You can also store a limited amount of items on the planet so you can use it as a jumping off point while exploring.
For $75,000 you can create a spaceport (for outfitting, getting crew), and for $150,000 you can create a waystation. All other buildings are not offered. You can also upgrade it later to a regular colony by adding 1000 personnel, 100 supplies, and 100 machinery.
These tech outposts do not count as a colonized planet, are not attacked by factions or pirates. Potentially a radiant event with a low chance may have a sabotage, mining accident, rogue AI event, etc and your outpost blows up/evacuates. The chance is lowered or removed with the spaceport/waystation.
Other faction's tech outposts can also potentially be found and raided/destroyed. For Nex, an outpost can be colonized with no penalty as long as there are no other planets in that system that are colonized/claimed by a faction.
Thoughts?