Triangle Push-Up Bra Inserts

Have worked since August to find an insert that fits properly; am status-post lumpectomy on the right. Ordered Oval Plus per measurements but this regularly popped out of my bra. Customer Service recommended a Triangle pushup (M). Unfortunately, this works only with a padded bra. otherwise is quite visible. Products seem well made but are regularly out of stock, and waiting is tedious. Customer service is as helpful as they can be, but I'm frustrated by the long wait for exchanges.

While the insert itself is wonderful and great quality. I wish the shape was a little less “pointed” - i’m so teeny tiny post surgery I was hoping for a more rounded fit. Perhaps I need to order the round pair too? Keeping this set for my bikini and work out bras.

I am afraid they may not stay out in my swimsuit …it does nor have insert pockets … I thought they would stay better