Antoine,
This is technically not possible. I raised a ticket to SAP and they confirmed that too.
If PA30 is in legacy mode, we cannot use decoupled apis to change infotypes.
We need to activate concurrent employment switches to let PA30 use decoupled framework.
This is a problem for us that we have 2 versions of code - one for ESS/MSS and one for PA30.
We are planning on bringing PA30 to decoupled framework.
Thanks,
Nag
