It appears I have once again been defeated by a glider. I tried extending the canards on the Chesapeake Sky Monster. No Joy. Added tail weight as before. Marginally better. Added some more...it still came down like a flying brick, but also took a right turn and the whole rear tail broke off. It still didn't glide that well and it's clear that weight exceeds the strength of foam board. I will repair it with some additional foam supports, remove the weight and either:
1) Give it to the grandkids. In their hands it will last a few minutes.
2) Give it to the dog, but he isn't showing much interest.
3) Point it down range and see what happens.
4) Switch to some of the E9 firecrackers. See option 3.