There's an archived thread on MTS about a buyable newspaper, where I learned how to do this. Later on in the post, joninmobile, and HugeLunatic are talking about giving the object a GUID, and HL says that it's not necessary. So, by my deductions, since that mod overwrites the game BCONs, it's the same as having game BCONs. Not sure if that would still cause the clash or not.

Yes, his mod overwrites the game BCONs, but your object contains the very same BCONs, just with different settings. That's why the last one to load will be in effect.
Your spawner would probably still work after removing the BCON and BHAV resources from the package, which would eliminate the incompatibility.

Okay thanks for clearing that up Gwenke, I've edited my post to reflect that it may clash with his mod.

squeeee! i have been wanting this for sooo long i can't even tell you! thank you, thank you, thank you!

I love you! This is the second item going directly into my favorites.

Thank you so much!!! Awesome!!!

I have EPs up to FreeTime: this object did not spawn either butterflies or fireflies for me. It might be a double deluxe thing. . . .

this sucks! it doesnt work and replaced my buyable fire!!!