Pole gaffs are the way to go if climbing thin barked trees and palms. Like you I live in the tropics where tree gaffs are useless ( IMO ) most if not all the trees I remove are thin barked. I really hate using spikes but they are handy in removals especially when taking down the main spar. I have done many removals w/o spikes once I have a tree nearby with a high TIP and the big spar has stubs for footholds. Just my 2 cents, keep them nice and sharp with the correct taper they have to keep original shape takes some know how, check manufacture's website for correct sharpening. I use ti-buckingham with soft wrap/w steel insert, very comfy, when in them all day add a piece of 1 inch foam to ease the pressure on the shins.
Paul.
Paul.