VRWorks 360 video nvstitch maximum output resolution

what is the maximum output video resolution for stitching using VRWorks 360Video 2.1 SDK?
Using the sample application I found out that the maximum output resolution is 4048x4048. If the resolution is higher the application fails with error “Error at line 261: Bad parameter passed” and last error message “Video destroy instance handle was null”. I am using a GeForce GTX1080 video card on linux.

According to the NVENC documentation the maximum H264 encoder resolution is 4096x4096. Why is the nvstitch maximum resolution only 4048x4048? Are there any resolution limitations in nvstitch SDK? Would it be possible to encode output video using H265 encoder in order to achieve maximum resolution of 8192x8192 (or at least 7680x7680)? I have searched through the source files, but the main part of the SDK is closed source so I couldn’t find any more details about the stitching process.

I use Insta360 Pro 2 cam and I would like to replace the Insta360 stitcher with VRWorks to gain more control over the stitching process. The Insta360 stitcher has the ability to output 8K stereoscopic video which is vital for my use case. Is outputting 8K video possible with nvstitch?

Thank you