Have you thought about using a heatgun (lower temperature available) to remove the patch?
The idea would be to have enough heat to melt the glue, but too little to make any structural dammage to the fabric... (might need to protect the raft fabric around the patch with thick towels or plywood)
I am not sure in which extend this would work, especially with the super glues you are using. But I think I might give it a try ('have the same issue here, althought I think that in my case, the patch might peal off before the material would break).
I used this process to remove a broken tip of my hiking pole, and was really impressed by how well this worked...
I will think over this in the next days. Any thought about this is welcome (before I make an irreparable mistake