Keep using dynamesh, but dynamesh at a really low resolution. Aim for this resolution while working (maybe a bit higher to avoid issues when dymameshing);
That's the way Dynamesh works, by design. It's always a lvl0 dense mesh. If you are working on a dynameshed model and want some kind of subdivisions, you can do a "remesh" at low resolution to get a new topology, then subdivide that and perform a "project all" to shape this new topology around the forms of the dynameshed…
Hmm interesting, I did my test here as well between triangulated and quad mesh. Quickly blocked out the mesh with Zmodeler brush and this is my result. The left side is triangulated and right is quad. Top showed the before dynamesh, middle after dynamesh, bottom after dynamesh without wires. Triangualted mesh does affect…
Ok, so use dynamesh if you continue to get stretching. You want your models to have the same poly density across the entire mesh. Dynamesh will do this. Just take your current triangle shape and run dynamesh on it, play with the various settings to see it's effects.
Try turning down the polish setting with Dynamesh, that may save your fingers and toes. Also, you can spread them out a little bit via transpose tool before the Dynamesh, then when you are done with the dynameshing process move them back closer together.