Honestly, in my experience mucous in stool looks like someone blew their nose in the diaper - so it would be stringy, clear or whitish, in various amounts. When Dylan has grapes he tends to get mucousy stools, and it looks just like poop and snot mixed in the same diaper
The problem with ebf baby poop is that it's quite loose to begin with (rather than the formed stool in ff babes) so it can be tough to tell. If you go over to the breastfeeding board there's an FAQ called the scoop on poop, and there are some pictures of different abnormal poops of you wanted to have a look.
And (((hugs))) on the dairy free - it's quite a pain
if you're having trouble with anythig specific let me know; I was dairy free for a while and Dylan still is so I will help if I can!