APS-C with metabones speed booster

Let's say I buy a Pocket 4K with a metabones speed booster. My Canon EF lenses should give me a result pretty close to having a full frame sensor. What's going to happen with my Sigma 18-35 Art that is designed for a APS-C sensor? Am I going to get vignetting? Does that mean that I should buy two EF to 4/3 adaptors, one speed booster and the other one without glass?

Those of you using the speed booster, anything I should know about? How reliable are they and can you feel quality loss on the edges?

Depends on which version you buy, the 0.71 version should not vignette the Sigma Zoom, as trsted on thr Panasonic GH5S. The original BMPCC Speed Booster (0.58) will not work, as it was designed for a 1-inch sensor, not a larger MFT sensor.
Cheers

I’ll have t wait and see what they will come out with for the pocket 4K. Metabones didn’t announce any official product for this camera yet. But they do mention that the 0.58 is not compatible : They cannot be attached to standard Micro 4/3 cameras (cannot be attached to GH5, GH4, GH3, GH2, GH1) and BMPCC 4K body.

The official one for the old pocket is a 0.64.

The bmcc one is 0.64, the old pocket one is 0.58. Both would vignette on the pocket 4k with the Sigma 18-35.

Both would vignette with any lens, they were designed for much smaller sensors. That said, the new Pocket does have a HD window mode, thst is smaller than a S16/1-inch sensor, and the BMCC one might work in Window mode, if it’s optical block does not reach too far into the Camera. The BMPCC SB optical block reaches too far back and may not fit, it does not work on the GH5S.
Cheers