Once I also thought about the same thing and started using a soft and thin leather insert for the holster, in order to avoid scratches and sweat on the gun. But then it seemed to me that such a liner looks somehow unprofessional and I decided to change the holster. Using the website
https://ballachy.com/best-holster-for-glock-43x / I was able to find an excellent leather holster, which not only fits perfectly, but also fixes the gun well so that it does not hang out. I feel much more confident now.