They look VERY healthy and bright !! Congrats, you are doing a GREAT job. Looks like they are also sweethearts of snakes.
Honestly, unless they show more signs of something wrong, like refusal to eat, weight loss, looking dull, acting "off", I would just continue doing what you are doing.
Make sure your husbandry is spot on (heat AND humidity)
I'm not a fan of taking snakes to a Vet "for a checkup" unless something is obviously wrong. Then of course you should.
But they look healthy and great, they are eating well.
You will risk that the trip to the vet itself causes problems. The stress of it, the temps there (usually quite cold to keep bacteria growth down).
Loose skin can cause the popping. Are you sure they shed the skin over the nostrils? Is your humidity good? Do they shed in one piece and without issue?
They really are lovely snakes!!
btw. I would go to feeding every 5 days. Their bodies work HARD during digestion. Its good to give them a bit of a break in between. Once you are at the size of a large pup or weanling, go to once the week. That's what I would do..