Thanks for the additional and excellent tips, Chinook!
When I built the bike up in January 2018 I had to pull the rocker pivot axle out to get the dropper housing around it within the seat tube. At the time it slid in and out quite easily. When I recently removed the rocker I had to drive the axle out with a drift. I'll definitely pull this and the main pivot axle at least every 6 months to clean and regrease them henceforth. The taper nut for the main pivot collet was also tough to get out so as you mention, I'll regrease it too.