I'm interested in this too, as I am getting very close to this phase of my build.

I seem to recall some challenges this way from our PMD build, which was probably less tricky than a Chester Yawl that way.  You're on the right track with the squeegees and such--we kept doing that until the epoxy really started to set up so that the fiberglass didn't have as much opportunity to pull away while we weren't watching.  Yes, it was tedious.  Good job to do while your favorite radio program is playing.

We also found that slightly rounding off the edges of the plank laps beforehand helped a bit.  A small fillet where the laps meet would help, too--the "inside" corners seemed to be the areas where keeping the fiberglass down was hardest.  It also helped to work in two stages: put a thin layer of epoxy down, wait until it got tacky, then work the glass firmly in place (squeegees) and wet out with another batch.  Not sure whether that idea was in the manual or if we came to that on our own after struggling with it.

May the Brute Force be with you, but not the Blunt Force Trauma....

.....Michael

     If possible set the boat at a 45° angle and along the centerline deal with just the lower half first. Roughly secure the unused upper portion of cloth above. Tacks and clamps work well. The off angle should give you an opportunity to work with gravity. 

> All of the above suggestions are worthwhile. I used them all when approaching the challenges brought into focus when adding fiberglass and epoxy to the insides of my Waterlust build.

Adding small fillets to inside corners at plank laps & frame-to-plank intersections is helpful, gives a bonding coat of unthickened epoxy laid down before glass cloth something to lend support to what comes next. Epoxy that's begin to cure's good for holding filleting material in place too; early in my build I was too quick in adding thickened epoxy fillets which then tended to slide off on the liquid epoxy underneath.

Even with extra hands (seldom available) need for frequent repositioning of my build gave me pause early on so I installed a Harken Hoister - chosen for storage of my canoe up in the open area underneath my garage roof - early in my build. Makes the task simple when I want to flip it, or roll it to an angle that reduces the 'verticality' of the surfaces I'm going to be epoxifying.

Used a goodly proportion of fast hardener too. Much of my build was in temps near 60°F and worrisome over time to full cure in MAS schedules made me choose it over the slow provided with my kit. Makes those tasks where you want a faster cure easier to plan for than sticking with slow hardener 100%.

I'm about to crack the seal on my fourth gallon of LV resin, gave some thought before ordering it whether the MAS FLAG resin would have been a better choice? Supposed to be thicker, not so liquid as their LV resin, maybe easier to handle on not quite horizontal surfaces?

Not sure if this is applicable, but I did large fillets on all the interior seams of the planks.  This considerably softened the transitions and made it easy to glass the interior of my PMD.