Push or compression starting a RT is not as straightforward as push starting a '64 Volkswagen. Several times early on in my ownership I rolled down a hill with ignition on and tried to compression start. A couple of times I skidded the rear tire due to compression, a couple of times the compression just brought the bike to a halt, and a couple of times it started but I ended up with an ignition fault warning on the BC. Success = variable. So yes, it can be done, but if you can use the starter, do so.
JayJay