I personally don't mow in reverse except when backing up a few feet while maneuvering around an obstacle.
If, however, I DID wish to mow in reverse, I'm doing my best to understand what is not SAFE about it. As long as one turns and WATCHES where they are going, there's nothing unsafe about it.
I fully expect that the switches were added because some careless person cut something or somebody while going backwards and not watching what they were doing. That person probably refused to be a stand up person and take responsibility for it and instead brough litigation against a manufacturer.
One of the problems in this country today is that there are too many people who want to blame their problems on others instead of taking personal responsibility for their own actions.
BTW. I found the reverse mow interlock switches on my Z-Force. There is one on each lever with both being normally closed switches in parallel with each other connecting the clutch circuit. This means that if BOTH of them are actuated at the same time, the deck clutch is disengaged. I simply pulled them out and turned them around, then tie wrapped them in place. This way they are never actuated.
As I said at the beginning of the post, I don't mow, per se, in reverse, but I do need to reverse a few feet occasionally when maneuvering. The reverse switches will simply wear out the clutch if left as delivered.
Have a great day,
Doc