Cute! So here are the data as I could find them by searching levels on J2O. There are four types of level that have generators for event 27 in them.

Generator is above a Belt: these should be actual functional MCEs that never generate a spike ball, but I'm listing them just in case:

• ab14ctf14
• ab16btl04
• ab19ctf02
• EZMaelstrom
• olcbabeatdown
• xlmcensored
• xlmtoilettown
• xlmuncensored

Generator is one tile to the right of a Pulze Light: these are the ones following that exact old eight-event MCE pattern:

• FF-7
• Hocus5lev
• labratst5
• rh_japan
• RtpWierd
• SXR
• SXR_Heat
• SXR_JazzBoss
• SXR_Rad
• SXR_Start
• SXR_Tech
• THEA1
• TSF XMAS START

Generator is four tiles above a Belt: these are all copies of one another, emulating a very specific MCE boss battle without quite knowing which events are important:

• clonejazz13
• Creamclone Xmas
• psychclone
• R1colony

No pattern:

• adream01
• Cracco Factory
• Cracco Practice
• Cracco Race
• crazylvl2
• jazzgeyser
• The Legends

In general, of the levels I've looked at, the spike balls are being placed in contexts that are already trying to feel really weird, so they fit right in anyway. But it wouldn't be hard to put in a very specific exception that the spike balls don't spawn if they're one tile to the right of a Pulze Light event.

ETA: I've tentatively implemented that "very specific exception" for 5.11. I'll leave this thread open for now in case people have other suggestions.