Larry, are you using a 45# bow with 450 grain arrows? The type of 45# bow will make a big difference-longbow,hybrid-high R/D,recurve-efficiency etc.
for example, If i had a hill type all wood longbow instead of my hybrid i would cut my weight down. my hybrid is bamboo and carbon which is very efficient at tossing a heavy log.
R

he asked if his bow and arrow setup will do the job on a cow elk.
since he is shooting 10 grains per #, he is not shooting a light arrow for that bow.
he is 5# over the required weight for his province, has an arrow of adequate weight, is used to shooting it, so is presumably competent with it.
i just don't see any negatives with what he wants to do.
everyone has a different idea of whats adequate. thats only natural.
my experience after killing more than 40 cow elk tells me that an arrow that is 8-12 grains /pound shot from a legal weight bow will kill just fine if you hit them where you need to hit them.
the gain from adding more weight this close to the hunt doesn't offset the difference in ability to hit the "spot" with a setup that is unfamiliar to him in my opinion.

Keep your shots close, broadheads sharp, pick a spot you'll be fine. Wait for that broadside shot........

sounds like a great setup to me.  Razor sharp heads and a lot of practice shooting.

I think Larry Knows a Little about Bows. Their might be a hand full of bowers that can match his Knowledge.

Larry