I'm looking to buy an Nspire, and of course I want to be able to run Ndless on it.  If I get an Nspire with 3.9 but a pre-J hardware revision, will I still be able to downgrade it via the RS232 boot2 flashing method?  I know this method used to work, but I haven't been able to find any information about if 3.9 has done anything further to block this.  From what I know, I'd guess it'll still work, but I want to get a second opinion before I make a purchase.  Thanks all!