I was bored and came past the Terradome system today and entered alone for the heck of it.
Wasn't terribly difficult to work my way through the dozen enemy ships you encounter here, just took a really long time, since they have 5-6 times the HP of normal enemies.
I failed on the ground part, of course, not because I was outclassed by the Undine, but because I just couldn't be in 5 places at once and eventually one of the engineers died and failed the mission.
Since the current rules of what makes an STF don't apply anymore anyway, why don't you enable Boffs for the RA version and scale down the space enemies a bit, so a solo player can beat the mission if he wants to.
It would require a well geared away team, where each Boff is capable of fighting of a couple of Undine after being rallied to a defense position.
Keep the VA version of the mission a a 5-man variant.
That way, the mission could serve as a prototype for new type of PvE mission content: