Yeah it's been discussed from early on in development and if it was ever going to happen it would've been years ago. Multislot part swapping will not be a thing. Not ideal in some situations, to be sure, but it does also have mechanical/gameplay side effects which are kinda baked into design now as well (like the ground being littered and not being able to properly use it for temporary space). Some of the veterans actually leave one or two extra empty inventory slots in order to circumvent such drawbacks, for certain strategies.
Multislot swapping actually gets far too complicated given many of the implications of swapping certain types of parts, so blocking multislot specifically is the perfect "clean break" from the massive number of special cases that would emerge and need to be dealt with (some of which would also end up not being possible to deal with, leading to UI inconsistency and headaches for players, too).
(Swapping parts is not just about inventory space, it also involves lots of mechanical implications when you get into special/unique part mechanics, of which there are already quite a few which are applicable, and many more coming. Having to deal with the nightmare of making it feasible to do multipart swaps, including, importantly, the ability to
predict the results of many of these kinds of swaps, would be an absolute mess. Predicting results is important both for players and the game, in order to give all the proper warnings and require confirmations where necessary. Over 100 new parts coming soon, many of the unique variety--expect yet more confirmation types to come
![Tongue :P](http://www.gridsagegames.com/forums/Smileys/default/tongue.gif)
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