As an Indiana resident, this interests me. Could you elaborate on how Indiana has called them out as unenforceable? And is there a state level substitute?
I'm also living in Indiana and 3 seconds of a Google search (indiana code nfpa 1127 were the search terms) comes up with a PDF as the second link.
https://www.in.gov/legislative/iac/T06750/A00280.PDF?&iacv=iac2010
That PDF includes the following text:
675 IAC 28-1-39 NFPA 1123; code for fireworks display Authority: IC 22-13-2-2; IC 22-13-2-13 Affected: IC 10-19-2; IC 22-11-14-2; IC 22-12; IC 22-13; IC 22-14; IC 22-15; IC 36-7 Sec. 39. (a) That certain standard, being titled as NFPA 1123, Code for Fireworks Display, 2006 Edition, published by the National Fire Protection Association, 1 Batterymarch Park, Quincy, Massachusetts 02269, be and the same is hereby adopted by reference, as if fully set out in this section except as revised hereafter. (b)
The following documents referenced in NFPA 1123 are not adopted, are not enforceable, and are for information purposes only: (1) NFPA 160. (2) NFPA 306. (3) NFPA 1122. (4) NFPA 1124.
(5) NFPA 1127. (6) Title 16, Code of Federal Regulations. (7) Title 27, Code of Federal Regulations. (8) Title 49, Code of Federal Regulations. (9) API Standard 87-1
I've highlighted the key text.
While this code doesn't have force of law in Indiana, if you fly with a club which I believe over 99% of HPR fliers do in Indiana, those clubs are either NAR, TRA or both and thus subject to the safety rules regardless. I would encourage you and anyone else to research the codes that are valid in your location.