Will the EOS R3 retain all its functions with an EF lens?

[Brewster]

Greetings to all , I am new here. I am considering purchasing a R3 and am wondering if this camera will retain all of its functions while using EF lenses with an adapter.
Thank you for any thoughts.

[March411]

Here's a link to a supplemental, I am not sure of the publish date.

Lenses Supporting Maximum High-Speed Continuous Shooting Speed

The AF stop button does not work on the following lenses when used with EF-EOS R mount adapters: Canon EF 300mm f/2.8L IS USM (1999), Canon EF 500mm f/4L IS USM (1999), Canon EF 400mm f/2.8L IS USM (1999), Canon EF 600mm f/4L IS USM (1999), Canon EF 400mm f/4 DO IS USM (2001), Canon EF 200mm f/2L IS USM (2008), Canon EF 800mm f/5.6L IS USM (2008). All other functions operate as normal.

[ctitanic]

I do not own the 400 DO but all the lens that I use in my R6 Mark I. When I buy EF lenses I check the manual to see if the lens is listed as compatible and if it's not listed there I look online for reviews of people using that combination of lens + camera. My guess is that this is what you are doing here. I do not buy the lens if I do not find anyone using that lens with your camera, in this case the R3.

Keep in mind that for example if you are buying a lens for portrait photography it may not that important to you if the lens+camera can give you 12 fps or a high fps. In this case, what is important to you is how AF works. Just my opinion.