Impose a PDF and add a slipsheet based on a variable field

[TM1981]

The second page in the PDF (testing-add-blank-page-newCoding_FPSUPPORT_EDIT) has the second page as the slipsheeet, it is set as an un-used body page and named slipsheet. Then in the rules I have this code on (OnRecordStart)

if(FieldChanged("gpb_lvl"))
FusionPro.Composition.SetBodyPageUsage("slipsheet",true)
FusionPro.Composition.StartNewStack()
 

gpb_lvl is my variable of 1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5

if I impose extra black pages get added and if I dont impose the slipsheet gets added 1 page past the desired place. (1,slipsheet,1,1,1,2,slipsheet,2,2,2,3,slipsheet,3,3,3 and so on)

If I remove the code FusionPro.Composition.StartNewStack() when imposing the extra blank pages dont get added and the slipsheet is always on its own page.

I have a PDF in the files called ideal_look.pdf that shows the desired outcome. 

I have attached my files, any help with this is appreciated

 

testing-add-blank-page-newCoding_FPSUPPORT_EDIT_02.zip