I have been trying different prep techniques for my grounds: WDT and sieving; but have suspected that some unseen factor is playing a role; however careful i am, and however perfectly even and fluffy the grounds appear in the basket before tamping, i seem to have variation in the flow.
But perhaps of more import is the evenness of the route of the grinds in every step after the grinder's chute. If the fines are unevenly distributed, but the larger particles are evenly spread, then will not the flow be uneven? I am here assuming the fines greatly control the flow rate.
Perhaps with more convoluted prep methods, the grounds can be well fluffed, but the fines might become unevenly concentrated within the mass.
So now i am trying to go straight from my doserless rocky to the basket, lots of knocking on the counter to evenly spread and migrate the fines down, then a little WDT to break up clumps a little, before evenly tamping. It seems to be working well.
Any comments or tips?

Its all pretty much speculation. If you found technique that works for you that's all that it matters.

I guess so, but i do wonder if many people find long lasting success with prep methods that involve alot of transfering of the grounds (from container to container). Basically, what i'm trying now is a vanilla method, with a small addition of WDT to counteract my doserless rocky's clumpyness; and hence i might assume the fines are evenly spread. Whereas with many transfers of the coffee, the fines may no longer be evenly distributed. Has anybody found success with a method like that?

I think most people don't transfer anything. Grind into basket, level, tamp and that's all there is to it.

My advice is to go back to the beginning and start over with as simple of a process as possible. If your Rocky is a doser model use it as a dispenser and flick away, distributing the coffee directly into the basket by moving the portafilter around as you clack-clack-clack the dosing lever. The same can be done with a doserless, but not as effectively, particularly with a Rocky. If your Rocky still has the portafilter fork on it get it off of there. it just gets in the way. To level the coffee off, tap the bottom of the portafilter in the areas and at a direction that distributes the coffee as evenly and level as possible.

To implement what Jim said, try weighing the beans and grinding per dose. After tamping there should be a good amount of headroom between the coffee and the screen. Adjust the amount of beans you grind to achieve that using a gram scale that can weigh to .1 grams. Use the lever's ability to begin the extraction very s l o w l y as a preinfusion. That pre-wetting will go a long towards minimizing channeling.

If that doesn't help, or if that grinder is making clumps that are difficult to manage, use the WDT or get a better grinder.

Yes, that's the process i have arrived at.
I do think the eveness of the grounds falling into the basket is important though. From that point onwards, moving clumps or larger grounds around the basket may or may not be having a predictable effect upon the whereabouts of the fines. It seems an even first contact AND an even final presentation is required.