You can see upthread that there are posters who have removed the thigh block.
I would caution you that unless you can try the exact same saddle without the thigh block, you really can’t be sure that it is JUST the block that is locking your seat in. The entire seat configuration as well as the thigh block make up where you sit and how much movement you get. Saddles built witha deep seat and a big thigh block are built expecting that the thigh block is part of the saddle, and massively altering them can open a giant can of unusable worms. Plus can you really be sure that it was merely your inflexible seat that caused her to “hate” it?
if throwing away a $2500 saddle because your Frankensteined your own thigh block removal if it doesn’t work doesn’t give your finances pause, then by all means go for it. I did not do it on totally anemic finances, but I would be hard pressed to spend $2500 on a hunch, knowing that it would make my saddle loose a ton of value because I cut off the thigh blocks.
If you can afford to just start over if this doesn’t work, why not just spend the money up front and get something that works for both of you?