In Buildxact, when you add a PC/PS/Allowance item we default the markup redistribution to the C option (within category).
If you'd like to change this default you can do it at an estimate level from within the estimate details section.
Go into estimate details and click edit
Update the PC/PS default setting. Note this wording will be different in different regions.
When the box is ticked the default will be the C option (within category) when using a PC/PS/Allowance item
When the box is un-ticked the default will be the N option (no markup redistribution) when using a PC/PS/Allowance item
For more on PC/PS/Allowance items and redistribution see here