@shiy10 thanks for the information and apologies for the lack of documentation. However, I think you guys seem to be on the right track here.
With regards to the middle piece: this reminds me a bit of the Ethos-U work, where BYOC was also insufficient because it did not allow use of compiler passes or automation. For that work, a BYOC-like flow was recently added which allows folks to customize the Relay-to-TIR transformation and the TIR-to-machine-code transformations while still allowing core compiler passes to operate on the TIR. And, the standard Relay-to-TIR pass was extracted into TECompiler. You may have already seen this, but wanted to point it out here in case you haven’t.
cc @mbs-octoml @electriclilies @mikepapadim who are pushing to make the core compiler flow more flexible to allow for device-specific optimization.