That detailed EV based exposure chart looks to be Fred Parker's Ultimate Exposure Calculator (his punchline being the calculator is YOU!) Any link to it now leads to a dead end. Good you printed it out.
When I was using film with M2 and then a Rolleiflex and some other unmetered cameras I got used to the certainties of incident light metering with a handy Gossen Digipro F which I still use. The M6 meter is reflected light of course. I would carry the hand held meter even using that camera once I was no longer chasing small children with the M6, the reason I upgraded to a built in meter and added a 35mm lens. But the M6 meter is scarily good and I soon relearned to just trust the two red diodes. After all the M7 is not a camera you hear people getting bad exposures with. That's got to be a great camera for those autumn days with scattered clouds where the shot might require two stops more or less with every passing cloud.
The digitals are also good but I am second guessing a lot with a test shot and then setting manual, or just starting with manual seeing if I'm right. I found that with a 28mm lens or anything wider I would get underexposure on account of so much sky in the frame. And blowing the highlights with digital adds to over-exposure concerns, not relevant with colour negative film in particular.
The most important thing about managing without a meter, or shooting manual with a meter, is that it increases engagement, and makes you think and try harder which is the way to get better shots.
As noted above, I would not be planning to take the battery out of my M6.
