I know of one fatal accident where the SOP for crew was to pre-select reverse on finals - KNOWING, FOR SURE - that the weight switch would prevent reverse thrust until touchdown.
Old Piedmont crews used this unauthorized 'technique' on the classic 737's, weight on wheels would pop the buckets at touchdown to give best short field perfomance at places like Roanoke, Virginia.
Along came the 737-300 and 10 feet radar altitude was used to arm the reversers, inevitably a few very hard landings occured as the reversers deployed prior to touchdown.