There is a way to make building maintain a PSI matrix - by setting in unit.dat order for that building - PSI provider (script).
There's a problem, however. When building with it (other than Protoss Pylon) is destroyed, PSI field remains on place, with no way to get rid of it. I know that it may be hardcoded, but I'm curious that has anyone modding experience related to it, which may help in solving this question

Might be better to ask at http://www.modcrafters.com/
Anyway it seems that only the graphic remains, and has no functionality, according to http://www.modcrafters.com/forum/viewtopic.php?f=19&t=110&p=1076&hilit=Pylon+aura#p1076

Thanks, for finding this clue.
Then, i'll just need to kill this overlay in iscript? But even when using original's one animation script, field still remains...