1) Pay attention to how high the main tire is above the ground (while on the cradle) before you start. I noticed that if the tire is less than or equal to 1.5 inches from the ground, wing install goes better. If the fuselage is higher than that (2+ inches), it goes badly. I'm not sure why. I think the extra pitch up attitude of the nose causes a tortional misalignment that requires more force to overcome. I would have thought that once the wings were flush with the fuselage seated in the lift pins then the tortional orientation couldn't be an issue. Anyway, by simply lowering the cradle to get the tire closer to the ground almost always fixed my problem - even though there was no apparent change in the wing gaps and hole alignments.

2) Use your "eyes" to align the spar holes first. If you can 'see' a misalignment, there is no amount of force you can apply to the pin to fix it.

3) If you see a misalignment of the spar holes in the vertical direction (so the assumption here is that the wings are tight against the fuselage and the fore/aft alignment is good), I have found that raising or lowering the CRADLE did a better job of aligning the holes than to raise or lower one of the wings. When you go out to the wing tip and "fix" wing height, you almost always cause the wing to pull out slightly or cause a misalignment fore/aft at the root (so you fixed one problem, but created one or two others). (This will be less of an issue for you with the electric rigger). However, using the cradle doesn't cause that problem at all, it is the ultimate fine adjustment knob. I like to assemble my wings so that the fuselage is a smidge too high when the wings are in, such that I have to lower the cradle to fix the gap. Because both wing roots are being lowered, gravity is helping keep the wings nice an tight against the fuselage as the cradle lowers. Hope that made sense.