Also had the dreaded Dot on mine and had to RMA it. Took about 4 weeks to come back, the good news is they sent a brand new model back as a replacement.That's frustrating. I turned it on this morning and the white dot was back. It went away much quicker this time, but seems if the projector is off for a period of time this will come back. So it seems like my experience is probably going to be similar to yours @SebastienR.
I was hoping to not have to send this in for service, but may have to reach out to Optoma.