Just a wild train of thought on my part... apparently some people suffer from repetitive boot sequence coups. How far fetched would be an idea, to try to embed the rEFInd in a pre-existing UEFI image? UEFItool could help with the image manipulation, maybe the rEFInd binary could be renamed and placed instead of some "factory" module responsible for the actual booting of on-disk EFI loaders... (if not for the boot sequence itself). I haven't tried this myselfs, based on past experience with trying...
BTW, is there a chance to add a "manual" line break in the displayed data? When debugging some serial comms, often the communication is "on demand", and it would help me to separate subsequent "instances" of activity visually on the screen. AFAIU, in 2.0.0.70, I have no option to just hit enter a couple times (with the newline getting "locally echoed"). Not in a hex display mode.
I'd love to add more than one upvote :-) This is exactly what I've been missing in RealTerm. Years ago I've written a simple piece of software for Linux (serial line hex-dumper with Curses output) that does exactly that same thing, but I don't have the time to port that to Windows and for various reasons I have to live in Windows most of the time. In Linux I could often detect timeouts as short as 10 ms. When debugging various serial-based communication protocols and fieldbusses, most of them request-response...