No, it's not separate. It's the same Inquiry.
Mark Kennedy was employed by the National Public Order Intelligence Unit (NPOIU), the successor unit to the Special Demonstration Squad (SDS), and both units are being examined by the Undercover Policing Inquiry. There was a lot of crossover between the two units in terms of both personnel and tradecraft (and those they targetted, and reported on).
This week's witness, like Andy Coles and Bob Lambert, was employed by the SDS. Every time another of these 'spycops' gives evidence, you think they can't get any worse. But this one has managed. And has been given anonymity by the Inquiry, so we only know the cover name he stole from a dead child used to spy on animal rights activists,
If you don't want to sit through all the evidence (much of which is available via the UCPI's Youtube channel - audio-only this week) you can check out the reaction videos being filmed by those who are attending the hearings in person: at https://www.youtube.com/@copscampaign6863/videos
If you're near the Sumac Centre in Nottingham, they're hosting a 'Spycops Info Hub' while these hearings are on, so people can watch/listen to the latest evidence and updates together (with food):
https://social.coop/@Veggies/113828963237555274
Kennedy was represented by infamous publicist Max Clifford for a while, but hasn't written a book. One of the women he deceived into a long-term relationship ('Lisa') contributed to this book, along with others from the Police Spies Out Of Lives group (including Helen Steel):
https://policespiesoutoflives.org.uk/deep-deception-the-story-of-the-spycops-network-by-helen-belinda-lisa-alison-and-naomi/
Another of the women Kennedy deceived, will be publishing a book later this year, which you can now pre-order:
https://www.hive.co.uk/Product/Kate-Wilson/DisclosureUnravelling-the-Spycops-Files/31397106