So I got these QoL ideas while playing X-Piratez but they may fit into vanilla so here goes.
Soldier's walking/running speed is adjustable in vanilla options. Thought it would be cool to be able to use slower speed but skip to destination with a press of a button, or to an event (reaction fire or enemy spotted or whatever), whichever comes first. It leaves us with pretty looking walking but with ability to skip. Feature would function similarly to shooting: have it set slow but resolve with RMB. With better overview on how the projectile behaves and path it takes by using slower speed. TU usage nuances are easier to stretch to our liking with slower speed but sometimes not required so we'd have the mighty skip.
Fastest setting on the other hand has unacceptable drawback of high difficulty to react to unwanted action (or change of mind), inability to fine tune destination orientation without using turning (saves TU), and just worse overview of pathing and enemy reactions to it.
The other one concerns those up/down arrows all over the place (buying/selling/manufacture/transfer). The one QoL we have is RMB for MAX but nothing in between. How about adding user-configurable key binds: 10/50/100/custom? Especially useful in frequent but temporary interrogations that occur in XPz, always resulting in click-fests.