I shot a video in 4K 30FPS and rendered it in Premiere at 4K 30FPS with synced audio and now added Toonit! effects in After Effects. I want to lower the frame rate to render a rotoscoped cartoon version from After Effects in a lower frame rate at 4K 15FPS. When I export from After Effects I chose to change the 30FPS to 15FPS and keeping the bitrate the same at 40MBPS and 4K and added to the media encoder queue.

I have never attempted this so I don't know if dropped frames will also drop audio since the end clip ends up a 1.5 seconds shorter.

Will this ruin the hardcoded audio by dropping half the frames? If so, is there something I could tune to successfully drop half the frames, keep 4K resolution and not end up with poor audio?