After this long I am still surprised how every time one of these discussions develops here on VAF, there are recommendations that jettisoning the canopy before a forced landing is a good option.
Everyone is entitled to an opinion, and everyone has to develop their own plan, so this is not meant to flame anyone, but I hope it will induce some very serious thinking (and possibly some thoughtful conversation) before anyone would settle on this as a good option (whether it be a forced landing in water or on land).
Even though we tend to get the idea that the canopy is very fragile (because of occasional cracks near drilled holes, etc.) acrylic is actually quite strong. Try and purposely break some sometime if you have the chance. I have done tests. It is not easy.
When RV's flip and the top of the canopy gets broken, that implies that a lot of impact load was absorbed by the canopy. Would you really rather have nothing between your head/face and what ever surface the canopy would have come into contact with (if it was still there)?
What about water? Anyone participate in high speed water sports (water skiing, etc.). Water at only 40 MPH feels very hard... and that is when moving somewhat parallel to its surface. Imagine what it might feel like if you where to be rapidly slammed into it nearly perpendicular to the surface.
I choose to have a canopy between my head and that hard water surface.
Back to forced landing on land.... what if the ground is soft... you got rid of your sliding canopy... the flip is violent enough that you still have fwd (now backwards) movement once inverted... the windscreen / roll bar assy. now acts as big scoop in the soft ground which induces enough fwd load to fail the roll bar by folding it fwd.... you may have now lost any escape benefit you hoped to have.
Going into trees... it is fairly common for airplanes to roll, yaw, tumble as they come down through trees... my preference is to have something between me and all of the tree limbs trying to poke inside.
I could go on and on..... maybe others have ideas as well.
Bottom line, when making a plan, think through the entire accident scenario. Not just a single aspect that you think might be the most critical point... a wrong decision could easily shift it from one thing to another