While it is absolutely a great idea to have an external programmer before modifying any BIOS, you do not necessarily need one to make an initial dump. Actually, in most cases you can use for instance Intel FPT. I have just verified that my modified BD4 BIOS works in headless boot. It beeps a few times on boot code “D6”, but then boots just fine. The stock BD4 BIOS will probably behave the same way.
A very interesting observation I made from this test was that: Enabling CSM in turn stopped TBU (Turbo Boost Unlock) with UPT (Ultimate Patcher Tool) from working?!?! It got stuck on boot code “79” which is the norm when attempting TBU from UPT. Very interesting indeed, maybe there are many more BIOSes that are compatible with TBU after all, just by disabling CSM?