RSSP multi-line updates not possible with :{PARAMETER.PurchaseCategory} variable in exp type VS

Summary:

Dear Oracle,

we are testing RSSP for the main part of our project-driven business, but have found a major issue that we cannot use any of the multi-line or summary level editing options for the PPM cost collection flexfields as the expenditure type uses a line level variable, the :{PARAMETER.PurchaseCategory}. Right now, if we try to use any of them, the expenditure type flexfield is mandatory to enter, but without any values in the LOV. So it blocks entry of any project segment.

As you understand only to be able to use single-line-level editing severely impacts the performance using RSSP, and we would need your help to point out any workaround. Or do you think we should log an SR for this?