As most of you know if you spam MF you will clip the tic and it will never happen.
The way around it is inelegant but works.
You must create this macro in game macro editor and not GSE.
/castsequence reset=target Moonfire(Rank 12), Moonfire(Rank 11), Moonfire(Rank 11), Moonfire(Rank 11), Moonfire(Rank 11), Moonfire(Rank 11), Moonfire(Rank 11), Moonfire(Rank 11)
The rank 12 DOT will tick, and you will get the initial damage from Rank 11.