Chain length - long or short?

Too short is worse than too long with 1x. Sounds like its ok, if the mech cage doesn’t contact the mech in the highest gear (smallest cog)
Park’s measurement is worth following

Speaking from experience… i took 1 too many links out of the chain, was too short, so had to replace it. Either replace or have 2 quicklinks in.

^ thanks for that,
I am probably there or there about

I like to run them as short as possible. Less chain to rattle and flap about!

I'll run it a is - but I can always take 2 links out

The ideal setting is exactly as short as you can make it but the absolute worst setting is "a bit too short", while "a bit too long" isn't realyl much worse than perfect so if you're not sure, it's a no brainer to go long.

For 100% safety, take the shock out if applicable and cycle it through, in the biggest combo of cogs. But you can cut it finer than that because the odds of actually using the whole movement in that super low gear are pretty small, you're always likely to be in a middle or high gear when you hit the suspension hard. Of course not all bikes will have the "longest" chain length while fully compressed so you have to be careful of that too. So it becomes a judgement call after that.

the odds of actually using the whole movement in that super low gear are pretty small, you’re always likely to be in a middle or high gear when you hit the suspension hard

As @Northwind says the min length ought to be ok in most situations as there's unlikely to be enough energy in the system at the low speeds you're going to be doing in the granny ring to fully compress the suspension. I think I always minimise my chain length with this in mind though I'm not sure it's a good thing with long cages and big rings as the longer the cage, the higher the chain angle.

For 11 and 12 speed experience tells me to start with the manufacturers stated method, anything else can lead issues as the top jockey wheel has a far bigger offset than good ol' 7/8/9/10

Not sure I entirely agree with the above. I've ruined a mech by granny ringing up a climb with slightly too short a chain and then forgetting to select a different gear before the descent. First sizeable compression and then bang.

I would go as long as possible for wide-range cassettes and 12s. So where you are now is fine. Yeah, there may be an optimal 1-link-less possibility, but you won't go wrong with your set-up as it is.

Not sure I entirely agree with the above. I’ve ruined a mech by granny ringing up a climb with slightly too short a chain and then forgetting to select a different gear before the descent. First sizeable compression and then bang.

Yep, not sure I agree either. Setting up a new bike at the weekend and I didn't appreciate just how much chain growth there was when the suspension compresses - it's a high pivot with a lot of rearwards axle travel, but even still I was surprised. Simply riding around the garden in granny gear and bumping over the path was enough to feel the suspension getting restricted by the too-short chain.

Given the bike isn't mine (Mrs a11y's) I didn't want the risk of issues so the chain's long enough to cope with full compression even in the granny gear.

Indeed. I thought my chain was too long, had a conversation on text with someone "knowledgeable" said what's the guide for chain length on 1x (duh! use ChatGBT next time! (just tried it, it's answer was spot on)) - he said it was big ring big sprocket +2. I said, what same as 3X, this is 1X. He said yeah. Cost me a new chain that 😆
(Hardtail, btw)

I wouldn't suggest setting it up with much less than the big ring at full compression but I'd happily go to the next link down but then I'm pretty mindful of it when cresting a hill and starting a descent so it's not been an issue.