Here’s the deal: No one should really care about modification. As I’ve stated, I don’t think undermodified malts even exist anymore in the technical sense. Even if they did/do, it doesn’t matter anyway. I think what happens sometimes, especially when step mashing is brought up, is someone thinks of a protein rest and then modification enters the picture. It’s a non issue because there just isn’t a malt available to us with a value of modification so low that it would be an issue.
In my opinion there are only two reasons to entertain mashing below beta rest temps:
1.) A ferulic acid rest for a Wiezen;
2.) Dough in low to allow for a live Sauergut culture to utilize its redox properties.
Step mashing, for me at least, is about beta, alpha and mashout rests, period. I feel it maximizes extract content (amount), fermentability, body, and foam. That may not be the case for others. That’s fine as well.
One thing it has nothing to do with as far as I’m concerned, however, is modification and therefore protein rests.