Is it true that overfilled and/or smooth implants have less risk of rippling?

Textured implants definitely increase the risk of rippling with no appreciable benefit. I would use smooth implants and not overfill them too much

Mentor overfilled implants are too overfilled, leaving rippling around their sides when the implant is sitting on a table top. You live in a country where Motiva implants are available. These are the newest and best implants in the world. They are optimally filled with either one of two available gel cohesivities ('Round' and 'Ergonomix'). Although technically not smooth, their proprietary 'nanotexture' has been around for over a decade and no reports of breast implant associated lymphoma and the lowest capsular contracture rate of any implant evaluated.

The capsular risk is low and the cancer risk is very low. I prefer the smooth round implants for a better feel, longer life span, and fewer risks. I have used many textured implants in the past and now only use smooth. For 15 years in the US, 1992 to 2007, we only had saline implants for most women. I realized that the textured implants deflated more often than the smooth because of increased stress on the textured covering. Also, the risk of late seroma is very very low in smooth implants, but higher risk in textured.