VERIFIED SOLUTION i

MailStream Plus presort is not putting mail to the same CRRT into sequential trays next to each other. Is this wrong?

Product affected: MailStream Plus™ 8.3.7, all versions, all platforms
As a presort is done, letter mail is put into trays.  As one tray gets filled with a Carrier Route's mail, the overflow will go into an additional tray(s).
They may even be at different tray levels, for example, one at CR5 and the other at CR3.  But each tray's contents are correct.

Then the trays themselves are sequenced, either in the default MSP order, or perhaps in the order of a customer using SRTFLn or SRTFLD parameters.  
The trays may be numbered so-as to come out in a different orders, but each tray's labeling stands on it's own. There is no USPS requirement (or even a reason really) for a CRRT's mail to be kept next to each other when they are in separate trays.
UPDATED:  May 15, 2019