I have a bunch of esp32-c3 and build system of capibaraZero make it easy to integrate it(like other device of esp32 family). The only problem with esp32-c3 is the absence of USB OTG feature.
Not really a requirement, you won't see USB section on the GUI. The capibaraZero is designed to support almost every device that support Arduino Wiring framework, so if a device doesn't support a feature, it will be hidden in GUI
I haven't looked closely at the files, but I wonder if there is anything stopping us from using the new C3 riscv version instead if S3.
C3 seems to be cheaper and more stable, but maybe the performance is a bit lower?