This idea was discussed at Logfest 2001, and the feeling was that doi was the appropriate cmavo: that these "foreign attitudinals" can be treated as invocations of a nonphysical entity by that name.
As a historical note, see also R.
When you don't have time to decide on .ue, .oi, or .o'onai.
do'a pe'i li du'e cu ni ce'u citno cmavo