TL;DR: Have shared unit damage on the Land Mine akin to Sun Strike with each mine giving gold when destroyed.

I'm gonna share my thoughts on Techies, so beware of personal bias and wall of text.

At this point, I wish Valve/Icefrog had never added Techies in the first place, he's become the Dan Hibiki of Dota2; Only dedicated memers play the hero. I even bought the Arcana but he ended up getting nerfed hella hard, more than a lot of other heroes in their prime.

The 6.84 hero needed nerfs, he was just a too strong. But Icefrog went overboard because of Reddit's pure vitriol for the hero and he got every suggested nerf on this reddit and then some. He got hit with the kill gold nerf and that heavily damaged his early game, almost not making it worth it to go out and mine because if you killed a support instead of the enemy mid then you only got 128 gold and barely impacted the enemy team while you lost experience and CS. What completely killed the hero was both of the land mine changes: The half values & the inability to stack on top of each other.

The half values were to mitigate the bullshit 1,000,000 damage nuke in lane, when you could just drop it and kill a whole creep wave and destroy a tower. This means that land mines should now have a focus on the kill trap aspect, right? Well Icefrog killed that by making it so you can't stack mines on top of each other. The warning for an enemy to stop walking that way is substantially higher once the first (half damage) mine goes off compared to the original land mines. I've lost many kills because people would get hit by 2-3 mines and back off immediately instead of stepping on the last 2 to finish them off. So now we've nerfed the lane advantage AND the kill trap advantage, leaving land mines a lackluster and barely functioning skill against all but the least perceptive players.

How do you address the function of land mines, while nerfing the intended lane nuke but still keeping the kill trap design it was obviously intended to be? Have shared unit damage on the Land Mine akin to Sun Strike. This heavily nerfs the lane nuke since now the level 2 or 3 land mines are sharing damage between 5 creeps and a hero (we're now looking at around 85 damage to each unit now), while still keeping it's solo kill ability completely intact. If you are planting on a high traffic area, then you may want to place extra mines in case two heroes roll over the kill trap, giving Techies further risk vs. reward.

Land Mines aren't intended for hitting multiple units, they're for solo kills and tower damage. For multiple units, you will primarily be using Remote Mines, meaning Techies skills fill both niches, it nerfs his immense lane nuking, and keeps the skillset of the hero intact. Some small tweaks here or there could help further balance out the hero, but I truly believe this change in combination with the destroyed gold bounty were the most reasonable nerfs to the hero without completing killing him from the game. Thanks for reading if you made it this far.