This is a hypothetical argument as I doubt there is any chance of seeing an S-53 or BV234LR on the NS in the future.
Don't know much about the S-53, however, if there are problems getting people out of a submerged EC225 with all its exits, have a look at how many exits there are on the BV234LR and figure out how to get 44 pax + cabin attendant out of that when it capsizes.
I suggest we confine ourselves to discussing the problems we have with existing NS aircraft as we are unlikely to see anything new arriving in the near future.