Hi Ronnie;
Interesting ... The last time I tried accessing the Delete buffer in an External DW the command(s) failed. Although, I must admit that was many PB releases ago.
I'll have to retry this in PB v12.6 and see exactly what happens. Hopefully, newer PB releases have addressed this deficiency. You have now peaked my interest in this area of the DW. 
Regards ... Chris
PS: we missed you last year at the PB Conference! 