Combat Sensors and ECM - the small Versions save space and are also rather cheaper than the highest rated ones. The higher tech large ones get more expensive, while the smaller ones get less expensive. Originally they were all listed separately, but this made their abilities stack, which was not intended, so I had to take that out. If you are still playing with standard set philosophy, and always building the most expensive ships, then you will probably want to go with the larger ones, and yes it'll be a bit more work at higher tech levels to select them in the design screen. I don't know of a good way around that without removing the smaller ones.
The smaller and cheaper ones are particularly good for ships that aren't designed as superiority battlewagons, or that just want to be more efficient. Particularly on smaller ships and drones, full-size sensors and ECM cost a lot and take a signifigant amount of space - the smaller and cheaper models then become an attractive choice, especially because in Proportions, these design sizes already have built-in combat mods that more than make up the difference.
Perhaps the full-size ones should actually increase in cost (and/or size) at a steeper rate, to make the choice more distinct. For large expensive direct-fire ships, the choice is pretty clear to go with the larger Versions.
Take a look at
the table HERE and let me know if you think it needs tweaking. Note that for example, with Sensors at tech level 10, CS VIIa is available, giving only +40 to hit instead of +49, but costing only 250 mins and 5 kT space, compared to 525 mins and 10 kT space.
I'm thinking maybe I should add more to the increased min cost of higher-level sensors and ECM. As in, maybe have them go up by 50 mins per level instead of by 25, and have them start increasing at level IV instead of level VI, and have them start getting bigger, like maybe +1 kT per level above III.
Note too that these techs still cost about the same to research as in the standard game, which only goes to level III, whereas Proportions goes up to level XV in each, and unless you're playing with multiple homeworlds, Proportions generally gives you a lot less research points after the early game. So... these issues mainly apply to players who dump lots of research into electronic warfare and play for a long time anyway, but still.
As for resupply depots having "emergency resupply," this doesn't appear during play. It's a tag so that the AI can be programmed to work properly with the mod. By telling the AI to build facilities that formally have "emergency resupply," they will build resupply depots instead of deciding that Cultural Centers look like the best kind of resupply depot, and then spending the next 2000 turns dumping resources into a colony that ends up producing nothing. There are quite a few meaningless tags you'll see if you study the data files, pretty much all tricks to get the AI to work properly.
PvK