It appears to me before booting the SCSI controller scans the entire bus querying each ID (and LUN) before it does any booting. Also whenever I change a device (CF Card added or removed at end of chain -- something I no longer do) when I go to HDToolBox or Media Toolbox I get a "need to update drive" request dealing with Last ID / LUN. From this I inferred that the controller wants to be able to write this info into the RDB or someplace on the drive; hence a CDROM would have no place to write this.
In addition how can an active terminator circuit "actively dampen" a signal without a power supply? A resistor uses the power of the signal itself to reduce that signals amount of voltage, but a circuit that attends to do a proper reduction of a signal voltage should itself be powered. If so, how can it do that without, lets say for the sake of argument, without termination power. If it does so with another power source, what is then the termination power used for? I'm not an electrical engineer and I think in terms of digital rather than analogue, but a simple transistor setup to dampen an excessive signal voltage still needs a separate power supply, or is there another way around this?
