I think there's definitely something to the "slow long jogging" approach. I've benefited from it several times, plus, it helps you stay healthier perhaps. I mean as an example, the tweaks i've had recently, I was able to jog below "tweak threshold" and still maintain/gain fitness. My ULTRA SLOW long running seems to have some serious potential, 15-20 min/mi pace but feeling like you're really running hard/fast -> short GCT, stiff but relaxed contacts, basically hours of single leg alternating pogos.
but ya, i've been slowly trying to bump up my long easy jogs. after my Coral Springs half, I wanted to make all of my easy runs ~1.5 hours. I've basically done that since, and it seems to be creeping up towards 2 hours. I've had thoughts recently of trying to get to 4 hours. I mean, if I can walk for 4-6 hours, I should be able to slow jog just the same.. maybe not the intense pogo style, but something similar to it (just less intense).
ALSO, it must be stated!! This stuff most likely has to happen on soft surfaces, not roads. It has to be dirt/grass/rocks/mulch etc, not concrete/asphalt. This is what allows you to maintain bounce, rather than having the hard surfaces "sap it out of you". Extremely important IMHO.