Don't know about the potential invasiveness of those species of Chionodoxa, Rita.
As you likely know, Chionodoxa forbesii/luciliae (the usual one) will not stay in place, like your lovely species tulips do.
The major problem is prolific seeding and being poisonous (viz. spreading not controlled by voles, etc.).
I'm seeing it spreading here from private gardens into other private gardens and into a public park.
I'm probably a traditionalist, but I don't believe that one individual should effectively put their choice in plants in other peoples gardens.
Guess the same goes for (not controlling) ones own dandelions.
Pictures I already used from a visit to Niagara-on-the-Lake one later April (below).
My own feeling is "no wonder they're moving' (that's a joke, I think);
but seriously what if their neighbours don't like this sort of plant distribution.
Once well established in this area, I can only assume they'll be invading the next.
Re this Chionodoxa: I'd say "Each to their own taste", but don't push yours down other peoples' throats".
I believe it's already classified as a noxious weed in Germany.
Suspect the time will come here.
Of course, Rita, the species you mention may well be more tame.
