Possible air or water logging problem on our steam system

Heatsink

We have a large steam air handler that had (or has) problems in the past with condensate getting logged in the horizontal steam coil. Few years ago we tried installing additional thermal expansion traps to act as air vents on our 2 inch steam lines before and after the coil.

These valves are installed on top of the pipes to only allow air to pass.
Seems to me, that these valves only remove air when the pipes are cold.
That would be great but we use 2 boilers in this system and sometimes the lag boiler will add air to the system on startup. Is it safe to say that air introduced AFTER there is steam in the main line will not be removed because thermal traps need to be cooler to open?

We have an F&T steam trap as well in the normal spot, incase anyone was wondering.
We did replace the horizontal coil a few years ago and I tried to make sure we got a steam coil that was rated for horizontal drainage but I can't say with 100% certainty I given the right one, though it did seem to fix the water logging problem.

3 years later and today it started doing it again so I am not sure. We plan to replace the guts of our F&T tomorrow.

If anyone is interested about this "water logging" problem, in the winter during high demands we would see the discharge air temp drop to almost the same as in air in.
Steam pressure was our normal 3-8 psi, control valve 100% open, new steam trap.
We figured out if we closed the supply to the air handler and opened a strainer just before the steam trap we could drain all the water out of the air handler coil. After this was done it would work fine the rest of the day.
Since then, we replaced the coil and installed 2 thermal type steam traps as air vents. that was a few years ago and today it started doing it again.