That may have been true at some point, but the 125B Hammond enclosure equipped with top jacks is a powerful thing. I would go as far as to say that I don't see a reason for a pedal to be smaller than that. When you do get smaller than that, the pedals become so small that if you make efficient use of their size by putting them as close as they can be to one another, you run into issues with them being too close together. This is much more true of the 1590A than of 3Leaf's enclosures, but even the 2mm difference in width between the 3Leaf Mini enclosure and a 125B is somewhat noticeable if you've got several pedals right up against one another. You kind of have to be an accomplished tap-dancer at that point. A row of top jack 125Bs, however, wastes almost no space and still maintains a usable spacing for most peoples' feet.
The other side of this, to me, feels like a question of values. To me, a custom-manufactured enclosure just doesn't feel like something a pedal needs. It doesn't impact the sound. Unless there's some very specific reason a pedal needs to be in a special enclosure, it just seems like fluff to me. Being in an appropriately-sized enclosure is important, but there are many sizes available to builders now. I would take a savings on price from using a standard die-cast enclosure than the minor space savings/aesthetic quality of a custom-made one any day.
I guess there's a difference in artisanship between two extremes: do we a) spare no expense and make the best product, or do we b) focus/optimize on only the parameters that matter to the sound and make the most effective product?
More and more lately, I find myself valuing makers who take the latter approach. A very good example of this is Barefaced Audio cabinets... they went out of their way to hammer out all of what a speaker cabinet needs to sound good, and then built everything else around that. It's not flashy, and the manufacturing is nowhere near as pornographic as some other cabinets I've seen, but what it lacks in those qualities it makes up for in being the best sounding cabinet that weighs less than some solid state heads and fits in the front seat of my car. They (and other makers) achieve these seemingly contradictory qualities by understanding what a product does and does not need in order to be most effective.