(In reply to :glob ✱ from comment #0)
As I sync between my work and personal systems, I explicitly do not want tabs to be shared across the devices. It would be nice to have a way to skip that step.
I'm not sure I understand this part of the request. That surface has no value without syncing tabs, so "skip" wouldn't really do something meaningful? As in, that surface is supposed to be a list of tabs from other devices (ordered by MRU). If we have no tabs access, there is no list of tabs, so nothing to display.
Product + UX have explicitly decided not to provide a way to dismiss the sync sign-up flow (including this step) - it was raised by engineering at the design stage. Once you complete the setup steps, you can toggle showing the list of tabs from within that UI (e.g. to avoid work/personal tabs being shown, as in your example). All the other surfaces on this page have alternative access points (colorways in about:addons, recently closed tabs in the hamburger panel, history menu, etc.) and so if the user doesn't want to use sync they can choose not to use this surface (and the button can be removed from the toolbar by the user, too).