I have an Ender 3 with Maestro, Bondtech, E3Dv6.
Flip the Z so the motor is on top (I cobbled together a mount, which was cake) , no dual Z
I messed with 0.9 motors before and they were more trouble than they were worth. Especially on a direct drive extruder. You would be better served by a geared stepper on Z.
The Hemera should be awesome
If you don't have a Pro you need to widen the Y rail. I would not just stick a single linear rail there. I would stay with rollers and a wider rail. 3 point is also preferred to 4.
Mine has the updated hard clear rollers. They are well worth it.
Put in a good part cooling duct with opposing cooling ducts. Might be a challenge to find for Hemera. I dislike the single sided ducts.