Hi! I am an in-between size also, and I always go to the larger size. I wear my rings loose, and in the winter, it gets super loose, and I can easily flick off my rings. It does not bother me, and I have never lost a ring because I don't walk around flicking my hands like that.
My VCA SA offered to add sizing balls, and I said no. This is because I already tried sizing balls with a Tiffany ring. The Tiffany ring was very top heavy, and because I already wear my rings loose, the ring kept flipping. The SA suggested I try sizing balls which I did. I found them very uncomfortable as I always "felt" those balls which made me mentally feel I have a Frankenstein ring. More importantly, I did not like how they looked inside the ring. I felt the sizing balls took way from the beauty of the ring (my now Frankenstin ring!), so I had Tiffany remove the sizing balls. I was able to resize my ring down one quarter size which helped a bit.
VCA will not resize the rings I have, so they are super loose on me sometimes in the winter (like now when it's freezing). For me, I would rather have them loose a few weeks of the year than to see the sizing balls.
On your Perlee ring... the inside of the ring is beautiful, a piece of art, and I personally would not want to add sizing balls to that ring. Besides, if you add the balls, won't your ring now be too tight in the summer? The ring is a wide band, so when your fingers swell, wide bands are hard to put on if they are snug. Tight fitting rings give that sausage finger look, so something to think about.
Before you go to a local jeweler to have your ring tweaked (does that void future VCA repairs?), maybe try some temporary ring adjusters. There are options out there, it may not look great, but it's a temporary fix.
Personally, I would wait to wear your ring for one full year, to experience all the seasons, before you do anything with it. Dont rush... I would not adjust it so quickly. Your ring may only be loose a few weeks of the entire year, and I would not add beads just for those few weeks (wear another ring that day if you are really worried it will fall off). I like to keep my jewelry looking pure, in its original state.
Here is an example of what I am talking about... there are other options to you can play around with.
Amazon.com: Invisible Ring Size Adjuster for Loose Rings Ring Adjuster Fit Any Rings, Assorted Sizes of Ring Sizer : Arts, Crafts & Sewing
Hope this helps.