Assuming the general rule of measuring chain outside of rear mech and adding 2 links is only going to work on a hardtail, do I really need to remove the shock and bring the swing arm up to somehow figure the correct chain length? Is there not an easier way? Any suggestions out there?

I’ve a single pivot Santa Cruz Bantam.

Ta

Just let all the air out of the shock

I let the air out of my shock.

Turns out on my marin at its longest point in the suspension stroke it is only one link extra needed to compensate.

Yup, put in “stretchiest” gear then cycle fully through the shock travel, it’s the only reliable way to do it. And it’s dead easy tbh!