I have a chart of what I think is the latest IPA (it includes the 
labiovelar flap (which is not yet in 
CXS, and about which bloody battles have IIRC been fought)). It 
contains a number of "proposed" 
characters, some of which I'm familiar with and which are in Unicode 
(such as the qp and db labiovelar 
stop symbols), and some of which fall into the "easy to read, but 
apparently not well-known" camp.

For example, there are "belted" versions of /l\/, /L/, and /L\/, 
symbolizing lateral fricatives. Also, 
the long-leg /r\/ is back (for the sound I might CXSify as /4_l/), and 
brings with it a long-leg /r\/ 
with retroflex hook (the retroflex equivalent, i.e. /4`_l/).

I've currently been dealing with them by using the COMBINING RETROFLEX 
HOOK, but that's obviously not such a hot prospect for the velar 
lateral fricative.

So, my questions are:

Should I just ignore them unless and until I need to use them?

If not, how should I best represent them in typeset text?

Would it take official IPA homologation before the characters make it 
into Unicode, or are they likely 
to slip in as part of one of the Phonetic Extension blocks?