Yes I understand. In this case is probably better (during saving this type of incompatible strategies as "Save stats in SQ3 format") to display warning report "Warning: this strategy is NOT compatible with SQ 3 format!" etc.
SQ4 has another structure of strategies, another building blocks - i cant see any way how to work with the new strategies in the old SQ3
Some strategies from SQ4 cannot be converted to SQ3 format, they use different architecture. This Bonus strategy is the example of that.