Spring RTS Engine

I described what I wanted to do to CMD_SET_MAX_WANTED_SPEED here. I'm not sure how many scripters read the dev forum, and I would like to know how big of a pain it would be if CMD_SET_MAX_WANTED_SPEED only affected movement that came after it in the command queue.
(Disclaimer: I know next to nothing about scripting)

Well, thats what I wouldn't want.. When my infantry take so much damage, they lose speed.. So I hope the change in instantaneous..

If this is about MAX_SPEED (75), it would be good if it changed on the spot. Also an idea is to use a percentage value, i.e. set 75 1.0 = 100%, 0.5 = 50% etc. Just an idea though, can be done with scripting either (if get 75 gets properly implemented as well).