Insufficient Sync Offset

[Helmanfrow]

Hi,

I've calculated that my microphone audio needs to be offset by -1547ms in order to sync with the video when I produce a screen capture.
The sync offset parameter, however, allows a maximum of -950ms which is insufficient.
Is there any way around this?
I've tried enablling "Use device timestamps" but that doesn't seem to help.

Thinkpad P50 with Quadro M1000M, NVENC H.264 encoder.
Focusrite 18i8 Gen 1 audio interface.

 

[Helmanfrow]

I've tried a number of things which have not resolved the issue:
Enablling "Use device timestamps".
Adjusting the buffer size in the Focusrite control panel.
Using different hardware encoders (Nvidia and Intel).

My only recourse is to fix the sync in post which adds time to my work.