You are worried about 206?
>230 is where I would get concerned.

Actually the ecu shuts off the A/C at 239F as long as the coolant temp switch is working.

Temps from Manual?
Fans on - 185
Fans off - 172

My experience - > 200 On, off around 197

As for coolant out the overflow?
I went through a HUGE problem with that.
Mine WAS HG and load dependent.
Actually - wasn't the HG - I fixed the problem by re-torqueing the head - go figure.

If the coolant is BOILING under 250F you have serious problems with either a cap that doesn't hold pressure, or the HG is blown, or your head is on loose which pressurizes your cooling system.

Is your head on right?

1991 AWD - SOLD - 1996 - 2008.
2001 JB E39 M5 - NA torque below 2000rpm is niiice.