Is there a reason why Amortization Vouchers are not available for selection when selecting vouchers

An Amortization voucher was created with payment type of supplier draft (DFT). The voucher goes to an Entry Status of "Postable" and then should be available for payment. We then go to the Create Manual Draft page to select this voucher for payment and after the Worksheet is built the Amortization voucher is not available to be selected from the list of vouchers. Attached is a document for recreating this scenario.

On the page "APD_MANDFT_SEL" I looked at the code behind the "Build" push button and how the list of available vouchers for selection is generated and I can see that it specifically includes only Regular, Registered, Reversal, Third-party, and Adjustment vouchers (V.VOUCHER_STYLE IN ('REG','RGTR','THRD','ADJ','CORR')). The list of vouchers is generated from the Record Field Peoplecode, APD_MANDFT_WRK.BUILD_WORKSHEET SavePostChange. The in list of voucher styles is defined in the variable &sWhereClause for use when inserting into the record "APD_MANDFT_WS" which is the record used for displaying the available vouchers to create manual drafts for.