games :6 Decks, S17, D9, DAS, OBO, No surrender

FREE bonus:

hand won with 5 cards pay 1,5 times

6 cards pay 2 times

7 cards pay 5 times

this seem to reduce the original edge (0.53%)
to 0.2 (more or less ...)

What I want to know is the optimal
strategy to apply here (hitting a soft 21 is allowed).

is it possible to use a count(with profit) specialised for these rules ?

Help please...