AGORI and other Oceanic gateway points question

[RMC]

My airline’s reroute track and distance manual identifies only three lat and long positions which can be calculated if rerouted from AGORI.
58N20W , 57N20W or 56N20W.

Could anyone familiar with Oceanic airspace please confirm these are the only likely three westbound positions we will be routed to from AGORI.

Thanks in advance

[RMC]

This is a general question regarding oceanic gateway points, AGORI used for lat long illustrative purposes. Thanks

[confused atco]

AGORI to 56/20 would keep you in domestic airspace until 15W.
AGORI PIKIL 56/20?

AGORI to 57/20 would probably have you sailing along the FIR boundary until SUNOT (57/15) then 57/20 so is very unlikely.

Probably only allowed to reroute 1 degree north or south of your filed track based on possible extra distance involved vs fuel on board?