Blockchaining as a gerund turns the technology into an activity, which is a subtly better position than the noun. Blockchain is a thing that had a hype cycle. Blockchaining is something you do, which suits the quieter phase the industry is actually in now, where the interesting work is supply chain provenance, settlement, records, and identity rather than tokens.
The .org is the right home for that quieter phase. Standards bodies, open protocols, research consortia, developer foundations, and industry associations all live there, and all of them need to sound like infrastructure rather than speculation.
It suits an education resource, a foundation, an open-source project, a certification body, or a publication covering enterprise applications. Any of those benefits from a name that reads as technical practice instead of investment pitch.
One word, verbal form, no hyphen, and it sidesteps the crypto naming conventions that have started to look dated.
The name is listed. Offers welcome.