some assorted notes from me:
the IRC system started in 2001 with the s4 and st4s. by 2003 all models had it (except 998s fe).
the red key is only used to code new or recode existing black keys. nothing else. do not give it to anyone for any reason except coding more black keys.
black keys can now be cloned by locksmiths.
you can turn off the immo function in the ecu software, so that the ecu will ignore the immo unit's commands (ie, don't start).
in that way you can remove the oem dash and replace it with something else on the monster or ss.
749/999, mts1000/1100 and st3/update 4s all have canbus communiction between dash and ecu, so will have some fault logged by the ecu and generally no air pressure input if you fit a non genuine dash.
any IRC equipped model oem ecu will be locked to that keyset and immo unit (in most cases, in the dash). likewise any replacement or dp ecu that has had a key coding procedure run on it will likewise be locked. as above, you can flash the ecu to turn it off.
later, non IRC models that run the 5AM ecu - 1098, 848, 1198, sf, hm1100 - have two black keys and those ecu are not locked to the original keyset and immo unit, so you can fit those oem ecu into an earlier IRC model and the ecu will function correctly. or flash them with an earlier immo active file without having to virginise or deactivate the immo in the file being flashed in.
these later model bikes can have the ecu flashed to turn off the immo function, but they still need a dash fitted to run. if the dash is not original to that bike it will show an immo fault. it will annoy you, but not affect how it works. they all have can bus communication between dash and ecu and often have some sensors in the dash talking via canbus to the ecu.
, you can't turn off the m696-796-1100 immo.