HI Stanchel,
A beta build of insync was once released for ARM64 (headless) but unfortuanely insync didnt follow up on it.
https://forums.insynchq.com/t/arm64-headless-test-build/17680
I honestly have no idea how complicated it is (albeit I recompile code for amd64 frequently for arm64) but it does seems that despite many requests from customers, this is not one of Insync priorities.
Other thread on the topic:
https://forums.insynchq.com/t/ubuntu-arm64-support/14983/18
https://forums.insynchq.com/t/ubuntu-16-04-arm64-support/14916
https://forums.insynchq.com/t/what-feature-do-you-want-us-to-work-on-product-updates/17446