Which old skool brake-blocks for all-surface touring?

Is it still Kool Stop? Have an old British Eagle tourer, Old Altus ATB-style cantis. 700c rims

I take it on gravel often, sometimes over grass. Anywhere except gnar really. The current M-System blocks are misshapen and worn but not a bad compound, quiet at least.

Need to be on a post like the Eagle2. Would it be possible to change to cartridge V-style pads (you can get them on a post) , or do those only work with V-brakes?

Kool Stop Salmons for me still. Braking is good and they always have far less (often no) alu embedded in the surface when I take them off for a clean/sand down. I cut that angled tip off as they wear flatter and more even that way, I think it’s a gimmick.
Should’t be any problems swapping them to a cartridge type, no.