I agree that the overall implication of the ability is underwhelming but acknowledge that any meaningful improvement would change the current Meta of GP as a whole. I would personally prefer a complete change of the ability.

Instead of a out of "combat" regen buff I think a cordial like ability that grants a refill either wholly restoring GP with a long 3 to 4 min cooldown (still much faster than waiting around), or set amount like X% or 200 - 400 GP with a cooldown similar to cordials but still separate would be better. An extra kicker but maybe to OP would be the ability to use it while on a node unlike cordials. This would change rotations and the like as it would be like have X amount more GP on the more urgent nodes like ephemeral or unspoiled.

This would allow anyone that grinds lv 70 to go back and take a more relaxed approach to high end nodes and collectibles while giving min-maxers a new tool to debate the use of. Furthering the games seeming efforts to streamline the game for newer or frustrated players.