I'm assuming that currently FTGL will not run on systems that have only OpenGL 3.X support. So this is a request to allow FTGL to run on systems that have only OpenGL 3 support (and which do not support the earlier OpenGL versions).
Without a report of a concrete issue running FTGL on an OpenGL 3.X system, this kind of request is a bit too vague.
One could just as easily assume it will run. If you know of a specific configuration where there is an actual problem (not a hypothetical one), I'd be glad to reopen this request. Plus, having sat in on OASIS discussions on 3 with demos from the major card vendors, there isn't yet any vendor I'm aware of that plans to actually drop support for immediate mode.