Audio desync in preview window when using virtual_oss

What is your operating system?

What is your Shotcut version (see Help > About Shotcut)?

Can you repeat the problem? If so, what are the steps?
Setup virtual_oss like:

virtual_oss_dsp="-T /dev/sndstat -Q 1 -S -i 0 -C 18 -c 2 -r 48000 -b 16 -s 1024 -f /dev/dsp0 -c 2 -w dsp.wav -d dsp -t dsp.ctl -l ldsp"

When playing video in the preview window the audio will be slightly delayed.

I realize I might be the only person using Shotcut on FreeBSD, so this might be fairly esoteric.

What can I do debug this more? Is there anyway to tell shotcut which device to use for audio playback?