It's obviously a question that depends on the writing. In a shorter season, if they try to take a single story which should have been a two-parter and stretch it out then that leads to filler (see Picard and Discovery). If they take the time to write other stories (see SNW) then it does not.
I am pretty sure that in every 10-15 episode season from streaming Trek, there's at least one filler episode. I don't know the various series well enough to tell just by the titles in most cases which ones were which. But even though most of streaming Trek has arcs, I'd say that at least one episode within each arc is largely meant to prolong the arc to make the 10-15 season order as opposed to "this organically needed to be its own episode and there was no sense of this where it seemed like the episode was just killing time."
It's infuriating since Joss Whedon already figured out how to do season long arcs that didn't feel stuffed with filler episodes and arbitrary delaying tactics back in the 90s, while still finding time to cheat on his wife.
The novel is really good. Written by Rodenberry himself. Loads of extra stuff, way beyond the normal cut and paste you get with those. It's fairly anachronistic from a canon POV now of course.
Definitely remember a few odd bits in that novelization. The SFS novel makes it pretty clear that David and Saavik were having sex. The TVH novel includes Sulu meeting his however-many-great-grandfather and has a longer, but funnier, scene of McCoy and Scotty arguing about giving the '80s transparent aluminum. Scotty: How could you not recognize this man's name?! He invented transparent aluminum! He's one of the greatest engineers of all time! Everyone knows his name! McCoy: Oh, you mean like Louis Pasteur in medicine? Scotty: Who? The TFF novel makes it clear that McCoy tampered with the computers so that Spock would think they're called marsh melons. Pretty sure Spock figures it out by the end.
https://www.theyboldlywent.com/trekbooks/2020/01/star-trek-the-motion-picture-novelization-review/ The story of Lori Ciana and Kirk is told in the The Lost Years novel BTW
Alan Dean Foster ghost wrote it. He also ghost wrote the "A New Hope" novel when it was still just "Star Wars".
David Gerrod ( or whoever wrote the tribbles episode) sued Roddenberry over the novelization and won.
Do the anti-poison filters in the pattern buffer eliminate things like alcohol? I do not think so, but if they do then the answer is none.
I'm sure the filters can come off with a toggle switch like a firewall. Geordi beamed all those deadly virus samples for transport in "The Child". Couldn't do that if the biofilter was permanently on.
Actually, now that I think about it, he might have sued Gene for the TNG premiere. Which, if you ask me, is something that I would not want my name attached to. YMMV.
SNW has already made two time copies of Kirk. Run off another one, and have that one age into present-Shatner.
I would say that we should take from one-last-times of many iconic actors that it's not likely to be worth it in general (see Harrison Ford in the last two Indy movies, Christopher Reeve in the last two Superman movies, Sean Connery and Roger Moore going past their primes as Bond, etc. And that's not even factoring in the uncanny valley-ness of current de-aging tech. Much as I've enjoyed Shatner and would like him to be happy, my preference is no.
It amuses me that Sunsweet prunes are one of the main advertisers during H&I's nightly Trek block of programming.