I'm trying to fiddle with a map editor to maybe join beautiful community of map creators and I've found something interesting.
If you put an amp gem on tech then un-check said tech in map general settings, amp gem will not return to your "gem pool" and will act like a normally placed gem - gradually providing player with some benefit. Player cannot take gem off this tech, and you can even fully hide tech button while forcing some tech on players.
I tested it on a very simple and barren map, using three techs for mines - cannon, defense struc and energy production and these techs worked both in editor and finalized maps (I haven't tried exchange, I don't want to muddy it with a test map. At least I hope I didn't touch exchange, I haven't even found "upload to exchange" button yet). Lathe worked, cannon was shown on top of a mine and energy from mine slowly increased.
I saw some maps with disabled techs, but I haven't seen any map where tech was forced on player that way, even on puzzle maps, where it would be reasonable. I might be wrong, of course.
I've also haven't found references to this idea in this section or bug section of forum. I might have overlooked some information.
Also, this idea might not be used because of a bug, when pre-selected techs would be stuck on 0%, I've experienced it on some maps and I've found one bug report about it. http://knucklecracker.com/forums/index.php?topic=21694.0
So, my question to experienced map creators - is it a bug? Is it working for me only? Does it work in exchange? If it works in exchange, can you direct me to some maps that use this feature?
UPDATE: I'm currently using beta build.
The bug may be related to reloading on the frame when the HQ was placed.
I hope that this is a half-done feature, as changing the UI to show such locked-in techs would cause this to be identical behaviour to a feature I requested some time ago.
What works in a finalized map, works in Exchange.