"Deathrain" equipped with Experimental Interface performs a boost action and then uses EI to drop a proximity mine.

Does it get to do the free barrel roll or not?

In other words, what comes first?

The "Then receive 1 stress token." from EI, making it impossible to do the free barrel roll due to stress

or

The "After dropping a bomb, you may perform a free barrel roll action." which is then perform before receiving the stress?

Thanks for any help.

As per FAQ, stress tokens are assigned at the end of phase. You can use PTL and EI for 3 actions.

So for our purpose I'd go with. Boost, drop mine via EI, barrel roll, assign stress token