To expand on what @KarstenI said, you will not limit the network by having MR32s in it, the MR32s will just run an older version. It does limit a few features that require a consistent version, like NBAR categorisation, but that is it. We have sites with MR32, 33, 34, 42, 52 and CW9166 and the latter have their Wi-Fi 6 features enabled (but not Wi-Fi 6e). We tested a lot of clients and found no major issues and the site has been like this for 2-3 months with ~2-3'000 clients per day visiting.
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