I have a 12 on my impact with Cisco mounts. 15 would be in the way to much for me to justify but it’s your money if you can mount it on the side wall just outside of windshield you’d be golden.
Here’s my 12″ on a 2019 Lund Impact 1775
No way a 15″ works in my opinion.
I have maybe 1/2″ clearance between the top right and the windshield and barely enough room to get my hand/s under to tighten the mount PLUS it really does a nice job of blocking your view over there
You will find yourself squinting a lot and straining your eyes on a smaller screen like that. I’d personally bump up to the Apex 19 if you’re serious about catching fish.