"most" is impossible to search. "mostpager" would have been better with a soft-link from most as default.

Anyway, how do I use it, I've sudo apt install-ed it. Scanning the manpage doesn't give me any great hints e.g. "most /usr/share/man/man1/apt-add-repository.1.gz" brings it up but the manpage shows control data; using as if it were man just fails (it thinks I'm passing it a file).

Hint? Or do I need to read the source ...

If I recall correctly... add to your .bashrc

export PAGER=most

or for my fish friends, add to ~/.config/fish/config.fish

set -x PAGER most

This'll use `most` everytime a pager is needed (i.e. git log), if you want to use `most` only for man pages, replace PAGER with MANPAGER

On fish same effect could be achieved by running

set -Ux PAGER mostU

If you prefer to keep fish.config cleaner, that is :)

Either

    export PAGER=most

or

    export MANPAGER=most

depending on whether you want to use most for all paging or just paging of man pages.