Able yes, there are trackers with secondary server settings. You can consider Teltonika, Topflytech, Suntech, Ruptela, Maxtrack, Galileosky, Concox. Just select model that suits you best, and verify that this specific model supports secondary server.
But with flespi you can turn ON this feature to absolutely any device (even for those, that are not supported in flespi). Just point the device to proxy channel and split the traffic between up to 3 platforms!. Moreover, it will not increase your device internet traffic usage. And you will be able to see raw traffic from device in pretty online tool - HEX viewer.
