You've described two wildly different adventures with
wildly different results and assumed that PC's deserve to call on the quest giver through blood ties that really complicate the discussion needlessly in too many ways.
In the first the players might be
establishing ties to a local herbalist alchemist or minor hedge wizard who is going to have regular needs and is likely to notice the potential of a future favor with interest in the form of being extra generous with an up and coming group of adventurers before simply calling on them would become an out of teach thing given the quest giver's current & expected skills. Maybe one day that quest giver could even introduce that party of well established & proven adventures to an archmage in need of well established adventures in his circle of contacts.
In the second the party already knows a freaking archmage. So far above the needs of low level adventurers that there's no need to care about a future favor with interest and the archmage passing the party up to someone more powerful in need goes to individuals like Eliminster full on Dragons and minor deities or something.
You've skipped the entire journey with a level jump and
nepobaby background trying to justify that bump as totally the same thing when done at a higher level.