Your general contractor is your project manager. Duplicating that function will add confusion, cost and complexity.

Agree. Your GC is expected to fulfill those responsibilities.

Our GC managed the kitchen reno, just like he managed the renovation of the entire house.

Same answer as above. For our kitchen reno, it was the G.C. and me. Like yours, our Kitchen Designer offers Project Management service, but she shared that it was mostly for clients who traveled a lot and wanted the designer to monitor/manage the work being done in their absence.

I will say that 3 years before our kitchen reno we hired a much larger company to build our home addition, and they assigned us a Project Manager from their organization. They run 6-8 projects simultaneously and that's just how they operate their business, assigning a designated Project Manager for each job site. Their Project Manager was basically my "on-site G.C."

From an experienced renovator: Yes, get a GC.

You DO want to pay for some connection between Design to Build, even if it’s not full project management. You don’t want them handing you a design and that’s it. “Design project management” is typically is not 20%. But it does consume some hours that need to be paid for. That is at least 5-6 site meetings with the Kitchen Designer with the GC and specific trades on site. That also means substantial project documentation, in a jobsite reference book, so that everyone is working from the right plan.

An initial design meeting should involve walking the as built site with the design in hand, with the caBinet installer and GC, before ordering cabinets. Or else you take the chance that you’ll need to build in wiggle room for it not being built according to plans. It’s a game of inches. And do not forget the inches that casings occupy. That’s a typical “we forgot”.

You’ll want a site visit to coordinate the rough electrical. Things get built in the way. That has to be somewhat fluid. I like sung retrofit boxes for some lighting, and just having coiled wire runs in the attic, to narrow down exact placement in the finish stages. Saves ceiling patching,. Gets pendants perfect.

You’ll want a visit when the cabinets are scheduled to start, to go over the plan (again) with the cabinet installer and GC. It’s amazing what can be forgotten about in 8-10 weeks time.

You'll want a site visit for the counter template. Communication with the templater is key to a good job. Having the homeowner there too, so there are no surprises, is the best course.

You’ll want a site visit for the start of the backsplash. Sometimes the tiles are 1/16 smaller you have to decide about a corner wrap, or centering on the cooking zone.

And you’ll want a “wild card” visit to help solve some problem that comes up. It could be the floor tiles are thicker than spec, and now fitting the cabinets under the soffit is an issue. It could be the installer doesn’t understand the locking system for the crown molding that forms its own mounting cleat. It could be that a lighting variation makes some of the cabinets look “off”. It could be concealed damage on the cabinets, and it’s a critical cabinet, like a corner cabinet, so creative solutions are needed. It could be a lot of things that come up, that you need design input to go with the build expertise.

The whole point of design, is having that input at critical points.