Would these fumes contains any appreciable amounts of HG?
Probably not but as a rule of thumb in swims dream a well working fan (above head extractor, or pedestal fan) is employed to blow away anything which is possibly exuded from the apparatus out the door/window.
Dont think any Hg would become gaseous in the conditions of the reaction, nor survive the reflux condenser.
Just out of safety’s sake, use the fan anyway, its a solution to a common problem in clandestine labs.