I feel like the system is still flawed however you do it, as they still are exposed to rushing exploits. The concern only factors in a solo tenno rushing, but I am going to say "Inb4 4manlokirushtowersquads". A coordinated squad (which is more than likely given the team based nature of the solar rails) can just get a team of 4 lokis equipped with power duration and a max rush mod and just storm through missions. I myself do it in a number of missions in the void. There may be other effective strategies, but I don't think anything else will be more effective at destroying a solar rail than a team of lokis rushing through a mission while enemies can't even retaliate. Heck, even minus the invisibility duration, they are still significantly faster than every other frame out there. It feels like the possibility of 4 Loki in a coordinated group was massively overlooked.