So...
The phpBB software has switched to an "event-driven" model for creating the HTML sent to your browser. Events can be triggered by comments that appear in the style templates. The prosilver template triggers an event called "overall_header_searchbox_before" that causes some piece of code somewhere (I haven't figured out where yet) to insert the breadcrumbs for the header at the top of the page.
However, the bottom of the page does not trigger this event, so the breadcrumbs are not installed -- you get just the Home link and the Board Index link.
I'll see if I can compare subsilver2 and prosilver to isolate what changes subsilver2 has that cause the entire breadcrumb list to appear in the bottom as well as the top. It looks like I just need to include an HTML comment that triggers the loading of a 'breadcrumbs.html' file, but prosilver doesn't have such a file, so...
Edit: Yeah, I don't see how prosilver is adding the truncated breadcrumbs at the bottom, so I don't know where to make the change. If I just include the HTML to trigger the 'breadcrumbs.html' to load, then it appears twice. Looking at the source code in the browser debug window doesn't help, because none of the HTML event triggering comments are in the DOM. If I get bored, I'll come back to this.
Edit^2: The breadcrumbs are where the second style-quick-changer is being added to subsilver2, which means I'm not going to be removing it -- if I do, it gets removed from the header as well. I haven't studied this new event system in phpBB3 at all, so I'm familiar with where to hook in to make these kinds of changes. I'll scan the phpBB forums for posts related to the style changer and subsilver2 and see if anyone has already made the change. (Some quick surfing on phpbb.com shows that subsilver2 was deprecated in 3.0 and meant to be removed in 3.1, but was kept at the last minute. The idea was to kill it in 3.2. Well, we're in 3.2 now and it's not gone yet, but support for it is waning. Apparently.)