The Schoeps is a very sophisticated and expensive mic. Can’t imagine it not working out.
My suggestion:
“PZM” Pressure Zone Mic, AKA Boundary Mic. PZM was a brand, but also a general descriptor. My favorite brand/ model of them these days is the Audio Technica Pro 44. They are popular conference room table mics that can be shared by two people, the pickup is that good.
Has a good omni pickup with some reach. Also great placed on the edge of a stage floor. Unobtrusive in that it’s a flat plate that can be gaffed to the top of the lectern or onto a nearby inside surface. You can tape it to a wall and the entire wall becomes part of the mic. Only issue would be if it’s on the top surface of the lectern and your speaker starts laying papers on it because it doesn’t “look” like a mic.
If the guest is in, say, a wheelchair, *next” to a lectern, mounting the Boundary mic on the side of the lectern next to their elbow will pick up pretty well.
I once mic’ed an event with several of these, and the guests didn’t believe they were mics, insisted on obtrusive “stick” mics on table stands instead.
Some lavs come with a boundary mic attachment that “converts” the lav into working like a boundary mic. I’m a little skeptical of that approach, but it’s also very unobtrusive. In those cases, in my experience, it needs to be taped down very firmly to a hard surface to work best.