I've read where others have used the same method of pouring epoxy into a hole near the blocks but after actually cutting open the wing and getting a good look at how poorly they are secured to the wing structure this wouldn't be my first choice. Not to say that this method won't work, it just wouldn't be my choice. There is a huge gap between the top of the blocks and the top wing skin. The sides of the blocks are poorly secured to only one rib and the ends are glued to the trailing edge spar. They were pretty easy to remove without any damage to the wing structure. Filling this area with epoxy at best will probably just transfer the shock load to the top wing skin which is only balsa. It also will most likely make it much harder to remove them later if the need arises. If the stock blocks would have been orientated side to side and closer to the CG, I most likely would have never cut into the wings right from the start, but as it turns out I'm glad I did.
Another area of this plane that did not get enough thought are the rudder and aileron servo locations in relation to the hinge lines. The rudder horns cannot be attached perpendicular to the hinge line due to the angle of the control rod. The horn must be attached to the rudder so it points at the servo arm with the rudder at neutral. Moving the rudder from side to side creates weird angles at the horn. I got around this by using a steel clevis (a quality clevis, not the ones supplied as mine were junk) on the servo arm and a ball link at the horn. This worked well despite the ugly geometry of the whole thing. The aileron linkage turned out much nicer by pointing the servo arm toward the wing tip and lining up the control rod 90 degrees to the servo arm. I was then able to locate the aileron horn perpendicular to the hinge line and the servo arm. This also allowed the horn pivot point to be on the hinge line.