bosch makes DW with faulty impelers and then doesnt sell spare parts to fix. Thankfully PoC had the part, not cheap, but better than a new dishwasher. Follow the YT vids on disassembly and you should be good to go, and good luck..
Note: some vids show the kit coming with a notched washer for the shaft, but this is not included. It didnt seem to matter using the old washer.
I agree, a new locking plate to be included would make sense. Over time it becomes brittle in the inside (outside is pretty normal)