No weld fumes are safe. I am not suggesting that you should breathe any fumes. All I'm saying is the fumes are no more dangerous than welding either steel, or aluminum. The zinc coatings in galvanized steel are very dangerous. Never knew about the beryllium copper. Wouldn't have ever considered welding it, but glad for the info.

All I can tell you is aluminized tubing welds like any steel tubing, is sold as directly weldable, and other than the fact that the aluminum rises to the top of the puddle, working with it takes no additional steps. I've never had an issue with its appearance or strength. Your results may vary.

Use as much caution as you see fit. If you don't mind the extra work of removing the aluminum, go for it.