SteadyGains, muscle undergoes fiber hypertrophy with very little (if any) increase in fiber numbers. Muscle fibers are muscle cells; they are alive. Collagen fibers in connective tissue are not. Increases in fiber length or fiber diameter comes from stimulation of fibroblasts to make more collagen subunits which spontaneously assemble when dumped outside the cell. The best stimulus is tension induced.
Short, intense tension will probably add some length initially but more than likely fiber diameter will increase at a faster rate (stronger, not that much longer).
I’ve been thinking about the understanding that collagen assembly is spontaneous. This would suggest to me that PE maneuvers that give longer, sustained stretch at moderate forces or ADS after intense forces to give stretch to the collagen fibers which might allow for spontaneous assembly into existing fibers at a longer fiber length without the need for IPR.
Just a thought.