Thought I would give a little Metabones IV T update
I'm going out each day for my lunch walk exercise and making myself grab a different lens just to keep things fresh. For the most part I'm taking the A7Rii unless the weather is dicey then I take one of my Canons.
Anyways, my prior experience had led me to only have issues with the Sigma 24-105 F4 with the Metabones - it loses the F stop info and defaults into M mode an really doesn't work, you need to disconnect then reconnect the lens and all is good until a few minutes later.
Last 2 days I have gone out with the 70-200 F2.8 II - and now I am getting issues with this lens - except I don't have to remove and re-attach I just have to rotate the lens counter clockwise / left to 'reconnect' it - i.e. there is slack developing.
What I am pretty sure the issue is, is the pin that comes out from the adapter, which mimics the pin on the camera mount of a Canon body, is either the tiniest fraction too small or there is play in the pin which allows rotation of the lens (i.e. slack) and the rotation of a heavy lens (i.e. the Sigma 24-105 and Canon 70-200) because of the slack causes the connections of the lens to lose contact with the Adapter.
With the Canon 70-200 it started happening all the time today but I didn't have to remove the lens - I just had to rotate it back and the F Stop re-acquired and all was well - for some reason the Sigma won't turn back on and has to be removed and reattached.
i never bought the camera thinking i could do professional work with adapters and this sort of proves it - that said, for non pro work it is just an inconvenience