I’m looking for experiences, opinions, theories or hypotheses on whether it is neccessary to grease seatposts inserted into steel frames with internal anti-corrosion treatments applied in the factory. (ED-coating and such like)

yes, because the seatpost can still corrode.

Also, it takes 10 seconds, why would you not?

My Cotic frame had that kind of coating and my Gravity Dropper still managed to get completely stuck in place.

Destroyed the GD getting it out but my Soul survived.

If it’s not going to damage anything why would you not put some sort of anti-seize on? Anyway I would have thought the anti corrosion was to stop the frame rusting internally not to stop seat posts sticking.

On a side note I recently bought my 2nd tub of copper grease, first one lasted 12 years! Only bought one as I’d got lots of crap in the first one, hadn’t used it all!

I already did grease my post, but was thinking if it was needed, as I’ve thought that aluminium and steel have some sort of chemical way of bonding with each other and if the coating was going to stop this from happening, as it pretty much does the same as a film of copper paste or grease in between.

i use gripper paste on them.. means you don’t need to tighten the clamp so much, isolates the two materials, and seals the opening a bit from all the crap sprayed up over seat tube