Almost exactly what I do when shooting film to check exposure (but I use a 5D3).
Why do you wish to complicate your life? If it's for fun, disregard this post.
Exposure for film and digi at the same quoted ISO rating is not the same: not the same any more than it was when shooting b/w film or colour transparency material of the same/near nominal speeds.
Instead of unstable constructs you simply need a good hand-held exposure meter and the understanding of how/why it works.
When I bought my first dig camera -a D200 - I did some sunlit tests and thought that my results using the Matrix metering of the D200 and the incident light readings from the Minolta Flashmeter set to the same 100 ISO were identical. What I didn't know was anything about the ETR exposure needs of digital imaging. I imagined that I could translate my decades' worth of Kodachrome and Ektachrome experience straight to digi, but I was mistaken. Film and diogi are not alike; don't confuse them because you'll do your photography no good service. At one time early in digi history the mantra was to treat digi as tranny; later, that was discarded for the ETR belief, which I think works better, but is far closer to the 'expose for the shadows and develop for the highlights' idea behind b/w film usage.
I still have a pristine F3 but it lives in a safe, almost unused from the year it was bought to replace an F4s, which I ended up hating.