Today Capture One released version 14.0.1 that was specifically created to support the Capture One 21 collaboration with Leica Camera and supports the new Leica SL2-S mirrorless camera (see this dedicated page):
The new Capture One 21 version 14.0.1 service release includes (see full release notes here):
* Live-view support is currently not supported.
** Leica S007 currently has preliminary Generic DNG profile support.
The Capture One 21 Leica support list can be found here