Your post piqued my curiosity and I noticed you only have 2 posts at this point in time on the forum (IE - you just joined). So I went to the other post, your 1st one, on the same subject and see it is posted in the "other semi-auto pistols" forum, not the M&P specific line.

If I may make a suggestion - I would post a dedicated thread here in the M&P pistol forum. The Equalizier is in the M&P family (as is the Bodyguard) so it does belong in here. From a traditional perspective, the Equalizer is a different ball game than an M&P from the mechanical and form-factor perspectives, but S&W still has it associated with their M&P products which is what this forum is for.

Beyond that, it sounds like you have already done a good amount of digging on the subject. It may be that few manufacturers make what you are looking for.

Out of curiosity for myself - can you describe the use-case/environment where the specific class of holster you are looking for is required? Personal preference? Or service spec?