I don't use one during the archery season.
Success with hunting elk during the archery season can depend on your ability to call with confidence. I've used many calls including diaphragms over the years but nothing beats Phelps Game Calls! Given the manufacturing consistency of their calls, I know each time I open a package for a new diaphragm it will sound as good as the last. I've used others where this is NOT the case!
Staying dry and warm is critical to your backcountry experience as is having gear that is reasonable to pack in terms of bulk and weight!
Carrying the right food and enough of it is critical to your hunt! Archery hunting elk can require covering 6-10 miles per day so you need enough calories and protein to keep going! Staying properly hydrated is also critical!
As with all gear hunting elk in the Rockies, lightweight, packability and durability are critical features! A layering system is also critical to deal with the big temperature swings. I also choose base layers made of merino wool given they breathe, dry quickly if they get wet and don't retain order. Lastly, I also recommend buying the best rain gear your budget can afford!
With clothing accessories, the same critical feature apply including lightweight, packable, durable and insurance these items will keep you warm and dry.
Archery equipment can be a more personalized choice of the shooter so I didn't provide recommendations here.