I think you mean view mode, not visual mode. Something like this could do it:
nnoremap e :only|normal e<cr>
qnoremap e q:vsplit<cr>
With current version one should be able to restore exact split state, but this needs functions that were added after 0.8.
Of course, I could map :!less %c to e, but that doesn't allow me to toggle with e.
This can be done with less
actually, if you create ~/.lesskey
:
#command
e quit
and then run lesskey
to generate ~/.less
from ~/.lesskey
. See man lesskey
.