As Jorge pointed out, for practical use it probably doesnt matter that much for this particular developer/film combination. I don't use HC-110 so I cannot comment on that.
However I do use D76 and TMX sheet and roll films. My experience with this combination, and what I have read from others, is that tight control over all aspects is important (temperature, agitation, concentration, time, age of developer, etc.)
But, with respect, in strictly technical terms 1:3 further diluted 1:12.5 is not the same as 1:50
(1/4) * (1/13.5) = 1/54 not 1/50