Can I replace a three way switch with a smart switch in a Four Way switch setup

It will depend on the exact brand and model. With most brands, including GE, you will have to replace all of them with smart switches. However, as @Automated_House and @ritchierich noted below, there are two specific brands, the zooz and inovelli, which may let you use the existing dumb switches depending on the exact wiring.

Smart switches are not wired the same way dumb switches are in these kind of configurations. When you have dumb switches, the current is shifted from one loop to another when you flip the switch. Like switching track patterns on a model railroad layout.

With smart switches, the master switch at least has to always have power so that its radio can hear the next “on“ command. So the wiring is done differently.

People in the following thread can answer more specific questions:

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