as for use of the 240/x netblock, I think the netblock described in:
is far more appropo' for your application. I would strongly advise you do that rather than squatting on 240/4, as no patches to anything are required... or just use rfc1918. If you must squat, there's vast amounts of the US military and Halliburton space not publicly advertised worth making a political statement on, which will "just work" util that far off day when they return it to the global pool.
/24s are going for about 4k on the open market if you need truly public ip space.
As it happens, I've been engaged with john gilmore and others since august in exploring the hardware and software (and political) ramifications as to what it would take to make 240/4 generally usable. Test failures of note include many cisco routers and all of windows, can't take it. Windows apps need a recompile in one major case. Successes included ios, osx, android, and most modern linuxes.
We've developed an ever increasing (in)compatibility list (which we hope to publish when it stops getting longer) and have landed patches in the linux kernel, openwrt, several routing daemons, and openwrt to make it one day more feasible to deploy these and hope to take a proposal for public, global, experimental use of the experimental space up to the appropriate IRTF, IANA, and IETF groups, after we test interop with a lot more hardware.
Unlike early proposals (in the 2008 era), now that the de-facto standard for class-e is unicast (RFC1112 was written in an era when we thought routed multicast would work out), we hope to make these 268m new addresses more generally useful to everyone than rfc1918 or rfc6598 in the long run, but first up was feasibility, and then taking the tasks to the appropriate authorities, and for all we know that might not fly. I'm painfully aware of how one crash bug stalled internet deployment of ECN for over a decade.
If anyone here would like to know more about a saner plan to open up class-e, help out on the pending rfcs, or get in on the upcoming tests, please contact me offlist. I don't read web forums often.