Probably a good idea. The fruit get very heavy. I had to prop up the branches on my peach tree this year because there was so much fruit, the branches were stressed. BTW, fruit slings are the best use of panty hose ever! ;-)

I hope that's icebox size watermelons or else you may need pantyhose with briefs ;-)

You understand that canteloupe "slips". That is, when it's ripe, it falls off the vine. So without support, you'll be harvesting smashed ripe canteloupes that have fallen off the trellis.

No, I used to use my Mom’s old knee highs, (Moms panty hose, ick), I do not have any experience with cantaloupe or musk melons.

Then I didn’t use the knee highs, the melons did fine. I grew: Crenshaw’s, Watermelon, Winter Melon. I used concrete Reinforcing mesh as a trellis because I did not have ground space, I.e., up vs spreading on the ground.

Your trellis May need some help, depending on your trellis. My melons would get scars from the “trellis”.