Imo there is a big difference between people who just joined the server and people who are 1/2 laps behind because they had to pit, or whatever.
But the thing is that the people who just joined the server ignore the blue flags most. And imo, when you just joined, just make sure you're not on the racing line and not going full, so others know what to expect.
When I just joined a server I'll make sure I'm faster, no where near the ideal line when someone's approaching, or that I'm in the pits.
When I fall back one lap, I usually push a bit harder, and then I give the race leaders not as much room, but still enough, and I wait for a point where it's possible to get (slightly) off the throttle.