IHT - Close companies and 10 year anniversaries

Does anybody know how a 10 yearly charge is calculated when a trust was established by a close company?
In this case, there were three participators, who were each treated as making a share of the chargeable transfer on the way into trust (s.94 IHTA)
On the anniversary, do we treat it as three separate settlements, as we would if there were three direct settlors, and so can apply a nil rate band to each? or is there a single settlor (the company) and so one NRB. The close company provisions in s.94 do not obviously apply.

Confusing matters, I have also seen reference to a peculiar HMRC position (IHTM17085) which claims (oddly) that because it is an EFRB, the two scheme members are the settlors, despite it being funded by employer contributions. Not quite as good as three NRBs but two is better than one.

nb. this is not a s.86 employee trust but it is an EFRB.

Andrew Goodman
Osborne Clarke LLP