Hi Aditya,
Why do you want to stop update of S066? this will impact credit exposure, and customers credit visibility will be impacted.
Do you use FSCM credit mgmt? If yes, then you can check your customer old FI-AR FD33 and can try out removing risk class if any or the setup for credit check for low risk customer credit check does not happen. When order is not blocked for credit check the S066 will not get updated.
Or you can try by ABAP code to by pass credit checks for those customer see below the setup.
This you can give it a try, however SAP has designed credit management in such a way that
The updates of the exposure will be still visible with the parallelization of FSCM. The underlying databases S066 and S067 are used for the old “Credit Management” and FSCM Credit Management as well.
If you are using Credit Management ( FSCM Credit Management and/or “old” Credit Management) those tables are going to be updated and in transactions like FD32 the exposure value are build up from these tables that is the reason why the exposure is visible here as well (even if we both Credit Management in parallel). But anyhow users should check for the FSCM relevant credit control areas not more the old credit management transactions.