No, it is very relevant. Zwift uses a power curve to estimate your watts. The power curve is set to L4, not L5, so if you change it the power curve is no longer correct.
You should leave it at L4 even if it doesn’t seem to feel right… unless you don’t care about the accuracy of your power estimate, then change it to whatever you want, but just know that you are not producing accurate power.
See this thread: