You’re taping and filling square edge boards? Sounds like a tricky job tbh.
Personally I always thought adhesive scrim tape with dished boards was the easiest way. First fill to just get filler in the joint, letting to dry and then de nibbing so nothing is proud, then second fill to flush - if you’re good/neat you can get away with just these two steps and a light sanding, but usually end up doing a 3rd fill. I’d probably use easifill 45 or 20 depending on how much I had to do. A lot of the pros I’ve met use a ready mix for the final coat. It’s pretty wet but should in theory go on very thinly to get a good finish. Learning to get the right consistency when mixing yourself takes quite a few goes. Too stiff and it’s hard work getting it on, too wet and you’ll get it everywhere (although my understanding is that you need it semi wet when using paper tape).
You’re taping and filling square edge boards? Sounds like a tricky job tbh.
Personally I always thought adhesive scrim tape with dished boards was the easiest way. First fill to just get filler in the joint, letting to dry and then de nibbing so nothing is proud, then second fill to flush - if you’re good/neat you can get away with just these two steps and a light sanding, but usually end up doing a 3rd fill. I’d probably use easifill 45 or 20 depending on how much I had to do. A lot of the pros I’ve met use a ready mix for the final coat. It’s pretty wet but should in theory go on very thinly to get a good finish. Learning to get the right consistency when mixing yourself takes quite a few goes. Too stiff and it’s hard work getting it on, too wet and you’ll get it everywhere (although my understanding is that you need it semi wet when using paper tape).