What to tell, first some facts i guess.
The injectors open every 360 degrees crank movement (so once per revolution, twice before it ignites)
The ammount of fuel is calculated by the computer, the computer does not regulate fuel pressure, that's a mechanical process
If you want to increase the ammount of fuel over the full range (like when riding with modern 'clean' fuel)
there are several options like denting the fuel pressure regulator (got the tip from an old BMW mechanic)
find an adjustable one
strip your wiring and go for the 'race mod' by putting a resistor in there.
the race mod alters the length of time your injectors stand open, it can be increased with a maximum of 10% more or less fuel. (sounds a bit funny, is this correct english ? ;)
What also should be done id get the injectors ultrasonic cleaned (prefferably including the pump) every now and then (2 or 3 years, but if your bike is standing still in winter time; once a year in spring ;)
the ones from the 1100 have more flow so it's only wise if you can do it with a dynajet-test. Just mounting them will lead to an overrich mixture.
The reason why the injectors open twice is because it was easyer in development to let it sync on the ignition (every revolution, to bad it didn't use ignition on the camshaft like some honda's :)
rubbers for mounting the injectors can be obtained from any car parts store, they are .5mm shorter, but ok because it's all bosch licence built ;)
you'll say so what, and my reply would be 'do you want to pay 10 or 80 bucks'