Many "generic" flash manufacturers have units that are course to be compatible with Canon RT radio system. Most of them include "RT" in the model number of the units they offer that they claim to be compatible. Most of them are, for the most part, compatible with Canon OEM RT devices. When it gets a little messy is when you try to get two different generic "RT" flashes from different manufacturers to work together. It is then that problems seem to begin to arise more frequently.
Yongnuo is probably the best-known brand that makes generic RT flashes. Not all of their flashes use the RT protocol. In fact, most of their flashes don't. But those that have an "RT" in the model number, like the YN600EX-RT II. At the Yongnuo naming convention, the EX means that the flash supports TTL. RT means it uses the Canon RT radio protocol. Most Yongnuo TTL flashes are also capable of HSS, second curtain sync, multiple flash, etc.
If all you are going to use are flashes, then RT is not a bad way to go. But if you ever want to mix fast lights with more powerful monolights, be they battery-powered laptops or network-powered studio lights, you're limited to being able to tell those flashes to "fire" by plugging an RT receiver unit into the trigger port with monolight cable. To change the power or other settings, you must do it directly on the flash control panel. It is also almost certainly limited to manual power control without HSS, E-TTL, second curtain sync, etc.
There is another wireless system that offers compatibility with lights in its line from compact low power manual flashes with guide numbers of less than 40 meters to very powerful studio lights that produce more than 1,000 watt-seconds. This is Godox, which is also sold under various trade names. Adorama in the United States, for example, sells Godox products under its private brand & # 39; Flashpoint & # 39 ;. There are also vendors in Europe that sell Godox products using a private label.
Using a TTL compatible receiver with the Godox system allows one to have remote power control, use HSS, etc. as long as the flash is capable of doing the same directly connected to the camera's hot shoe.
That's something to think about before getting too deep into a flash-only radio protocol.