Agreed with Adam. I'd add/ask would SOC 2 Privacy criteria be part of your SOC 2 scope? or would you only be doing Security or which TSC? That'd determine the overlap.
We have 6 frameworks in our Vanta instance and overall the test cross-mapping is pretty good so there's not too much duplication. I don't have USDP or any privacy frameworks though (AI & federal frameworks in addition to SOC 2 & ISO 27001), so can't speak to the privacy ones specifically.
The one lesson learned is if you want to edit your control mappings across multiple frameworks at once there is no 'all' option in framework mapping so you have to search one by one through your multiple frameworks to update mappings. I have a feature request in for this cross mapping UI update but not sure when that'll get updated
