This is wrong wrong wrong. The front brake lever has absolutely nothing to do with the rear caliper. It only creates pressure for the front brake system. You keep feeding this false line that the brakes are linked.
The only linking going on is at the abs modulator which clicks shut upon activating the hill-hold feature. If there was no rear brake pressure applied by you before activating, it's not holding the rear brake. And certainly not creating rear brake pressure from the front brake lever. The hill hold is only holding pressure. Front pressure because it was activated, rear ONLY if you put rear brake on while the hill hold activated. Linked only in the holding function, not linked brakes. nada, no, none.
"Triumph has introduced electronically variable
linked braking on the Rocket 3, whereby when you squeeze the front brake lever, the ECU decides what proportion of braking power should be
applied on the rear, as well. This is primarily determined via speed, weight transfer and lean angle, leaving you free if you wish to add extra bite at the back by working the foot lever, which doesn’t also operate the front."
"All motorcycle models are equipped with a
partially integrated braking system, combined with the Anti-lock Braking System (ABS). This increases the braking efficiency when riding the motorcycle.
When the front brake is applied, a small amount of rear brake is also applied, allowing for balanced braking. The amount of rear brake application is related to the level of braking force applied by the rider through the front brake lever. Use of the rear brake pedal alone will only apply the rear brake."
"When all of the above conditions are met, complete the following:
▼
Squeeze the front brake lever firmly and quickly, then release."
"Hill hold control assists the rider in making hill starts. The system (when activated)
will apply the rear brake to hold the motorcycle in position. The system will then automatically deactivate and release the rear brake when it detects that the rider is attempting to move off."
Sure does sound linked. Now present your evidence.