Posting some previous work which explored finding non-trivial records in the grid for multiplication.
Pic attached shows the results for c*d multiples of records between c300 and c400.
The trivial record is in the "c=cd" column.
The non-trivial record is in the "a,b" column.
Non-trivial records are created using the "formula" column. The rules can be summarized as follows:
odd c * odd d =a=d, b=c
odd c * even d, d%4=0 =a=d/2, b=2c
odd c * even d, d%4=2 =a=d/2, b=c
even c * even d =a=d, b=c
even c * odd d =a=2d, b=c/2
The d%4=2 exception is because the resulting c will also be mod 4 = 2, and must be divided by 2 to create a valid record.