Firestorm viewer user here, but since the issue we (myself as well as all users I have had a chance to bring-up the subject with) experience can be reproduced in the Official SL viewer, it has been suggested I report it here.
After the load of a viewer with PBR-changes included, when using ctrl-alt-T to highlight transparent, prims and meshes - in particular "worn attachments" which based on action can be made transparent/invisible - anything from none to only a random subset of the actually worn prims/meshes will appear highlighted.
Prior to PBR changes, the very same objects always showed-up in ctrl-alt-T mode.
I discovered a 'work-around': by using alt-LeftMouseButton and zoom some 100-200m away from the targeted avatar/objects, and then 'esc'-'esc' back the view, then the non-renderd transparent objects are 'magically' rendered as they always did before PBR- changes.
This work-around is however a hassle when building or there is a need to position camera at an exact angle, as camera positioning of course is lost them.
Unfortunately, I cannot attach any images, as most of them would include objects of a maturity-rating not desired in an area with general access.