what are you waiting for, a documentary, I already made a post about this
does she have Shirou's soul: No, she meets Shirou in Sword Dancers
Ergo, without Shirou's soul, she does not have UBW
The rest is simple: Shirou can make swords in mass because he gets them cheap through element/origin, Ilya would be able to get them en mass through wishcraft, tons of prana and much higher quality circuits than Shirou.
Projection is a very common piece of magic, if not used because it's impractical: Ilya uses it due to sentiment for Shirou and a desire to emulate him, a desire she outright states in sword dancers
Thus she can have the demonstrated sword rain in Sword Dancers without UBW
And there is absolutely nothing in sword dancers saying she has UBW anyway.