The value for the number of Recent Submissions can be configured in dspace.cfg.
I increased the value from the default 5 to 20 to see if I could display more recent submissions on the Collections landing page.
In Manakin the number remained at 5 but in the jspui the number did increase according the value in dspace.cfg.
I was hoping I might quickly find something in the XSL that would explain the difference in behavior between the xmlui and the jspui.
I did not.