Absolutely. Style 9 can be worn however you like. If you would like a natural look, just wear them in a bra that has enough room to accommodate them. They will stay hidden low giving you a natural boost.
The effect can be intentionally bold, however, if you wish. Just go with a well-fitting cleavage-boosting bra with just enough room to squeeze them in. You can place them at the bottom of your bra cup or off to the side for a push up and in effect.

Yes — nights out, costumes, low-cut tops, and outfits with a bit of structure. She’s also brilliant for wedding and bridesmaid dresses, because those styles often need you to fill the cup area neatly and get a bit of uplift at the same time. When you want a confident chest line, Style 9b can be a really fabulous option.

As my styles get bigger, it becomes even more important that they’re properly held in place. Choose a bra with strong band support, and make sure you’re in the right band size — that’s what gives both you and the bra inserts their support. If you end up relying on straps, you’ll feel the weight more; straps should really be the helpful “finishing touch”, not the main support. It’s also worth tightening your straps now and then (they do love to loosen over time). Get the band doing its job, and you’ll find Style 9b can feel surprisingly comfortable — the lovely “pop her in and forget she’s there” kind of comfy.