This is the same situation as gohon-ippon.
If your opponent is pressed against the wall - you shouldn't
launch your attack but let them come off the wall and have adequate
room to move.
Similarly, if your opponent has no room to sabaki - either due
to the wall or other people in the line I think it is up to the attacker not to
launch a fully-fledged attack unless they have staggered position to give their opponent a fighting chance.