I have never capped a character's name in a synopsis. It just seems so comicbooky to me that I can't bring myself to do it. Though I've seen it done and I assume it's just one of those things everyone "knows", LOL.
I wasn't aware that an ALL CAPS introduction of a character has come into style, but it's basically mandatory in screenplays and treatments of screenplays, though almost no one writes treatments any more.
I do find it's helpful, however, to think of a synopsis as a sort of compressed screenplay. We're watching the characters come on screen, next the "inciting incident" that gets the story rolling (i.e. your hero and heroine meet, or something happens that causes a significant change to their lives and throws them together). Like characters in a screenplay, each of the characters in a novel has a "dramatic question," something they want but which remains just out of reach. It's a desire or a need that drives their actions throughout the story.
...and, well, you get the idea. For me, when I write a synopsis, I'm visualizing the story, I'm moving myself through it using the characters and their problems, etc. If I can "see" the story, it is so much easier to write, than just sitting down and asking, what comes next?
BTW, I'm currently judging 10 entries for a romance contest, all of which require a synopsis. Double-spaced. Not a single ALL CAP character intro so far.
Hope this was helpful?