CJ, Mach,
The discussion challenges an old and fragmented memory; 20yrs +
I do not recall any requirement to select engine anti ice on before engine start; switches were checked off during preflight checks.
A tech / sales pocketbook cira 1996 confirms the electrical description, but no procedural advice is given.
The bleed air discussion follows general theory, except for the 146 as below, and that bleed band is perhaps a 'red herring' during start.
The 'engine' anti ice system consists of two separate systems controlled by the same flight deck switch. The engine low pressure compressor anti icing, and the intake cowl. The front end compressor anti-icing uses air from the higher pressure compressor air (hotter later stages); the intake cowled taps the high temp combustor air (as for airframe anti icing).
During start the engine anti ice is automatically sequenced, as per the previous theory to off load the engine; vague recollections of lights coming on then off during start.
Were there any changes in procedure after the 'rollback' mods - 146 only; if so then the RJ should differ ?