I'm nothing beyond a novice writer, so take what I mention with a grain of salt. Within what I'm currently working on, I have numerous situations wherein I need to emphasize verbal speech. Though I may be incorrect (web advice is never guaranteed and where I found it), it was suggested that there are numerous ways of denoting volume/intensity/pitch changes without relying on what we all know as the standard.
Ex.:
"You better listen to what I'm saying!"
"YOU BETTER LISTEN TO WHAT I'M SAYING!"
"You better listen to what I'm saying!"
"You 'better' listen to what I'm saying!"
"You 'better listen' to what I'M saying!"
"You better listen to what 'I'm' saying!"
How do those read to you? I'll let the experts tell us how valid they are or not.
As an unrelated side note, I've been playing with italics and punctuation to convey individuals conversing over comms' (radio traffic). Again, this may not be proper so don't go by 'my' advice, yet I like the way it turned out (for the record, contrary to many folks thinking and perhaps even publication standards, I tend to write speech in italics).
"Central… What’s my location? Over."
‘Reaper-379, Central Dispatch… You are at 13-M-1-West. The structure west is adjacent to 13-L-4-East, over.’
"Roger Central… out," Kae finished up, looking to Cub.
Point being, if it is proper, why limit your use of punctuation and simply use caps?
K2