The problem is the coil lockout system is terrible in design. Here's a few reasons why.

- Like you said it makes it a lot tougher for FCs to include everyone in raid groups. More of then than not someone will be left out. This wouldn't be as much of a problem if FC members that already completed coil can go back and help the others that want to get them done. I'm one of the leaders for my FC and it really pains me to be unable to include everyone that wants to do coil into our coil group because there aren't enough people who main tanks to form more than one raid group. Go level a tank you say? I'm working on that myself and it will honestly take about a month to get a tank geared up well enough for coil because of the other time-restricted lockouts.

- The design also conflicts greatly with the ratio of tanks to total players. There are simply way too many DPS/healers compared to tanks and this is made evident by the DF queue timers. What tends to happen is that the good tanks will easily get into static groups, while the others just get left out hoping that maybe some tanks will join their coil groups in PF. Because these tanks cannot join or help other coil groups once they're done their runs, a significant number of people have to be excluded by design.