Fumble before crossing plane = turnover
Fumble after crossing plane = irrelevant
Quite different.
Again, the suggestion is to make the crossing of the plane more significant than surviving the ground. Your focus is the idea that it isn't a catch till it survives the ground, which is of course what the current rules are. The suggestion would be to insert a check into the flowchart right before the 'survives the ground' check, such as 'under control when passing the goal plane', and if yes, it is a catch and a score, regardless of surviving the ground. It would be harder to officiate, but it would have made the Dez Bryant and Jessie James plays become what I think most fans feel is more inline with their expectations. Of course, I'm fine with both of those being incomplete!