Is hanging from the front wheel problematic for the forks?
It can be – but it depends on the fork. I had a couple op pairs of Rebas back in the day. There was a little rubber gasket under the Gate knob (from memory) which wasn’t really up to the job, and the damper used to leak a tiny amount of oil when the bike was stored vertically in my shed. I ended up getting both pairs serviced by TF Tuned – they were aware of this problem and replaced the gaskets on any Reba they had in for service as a matter of course.
Never had this problem with the Marzocchis I had at the same time, nor Rebas or Revelations I’ve owned since.
I seem to remember one piece of advice was to cycle the shocks (AKA carpet test) when you got them down.
Also – in theory – storing them like this allowed oil to flow back towards the seals, lubricating the foam washers and keeping everything a bit better lubed.
Also a while back: DH bikes with (from memory) Hope Open Pro brakes had to go on ski lifts in the alps hung from the rear wheel, so as not to introduce air into the system when everything was heated up from a long run with lots of braking. Seem to remember it particularly affected the Giant ATX 1 for some reason.