I originally posted this in the Echoes subforum, but I was recommended by another user to post it here instead.
https://serenesforest.net/fire-emblem-echoes-shadows-valentia/miscellaneous/sub-quests/
This page is very messily laid out. The quests seem to just be listed in a completely random order. I think it would be much better to list them in order of when the quest first becomes available, and separate the quests in the list by location and/or chapter for ease of reading.
I also know for a fact that the list is incomplete. The rewards section for the quest "The Sommelier" doesn't list the Mila Statue that you can get after completing the quest. You don't get the statue directly from the quest giver, but completing the quest causes it to spawn in the Thieves' Shrine near the treasure chest with an Iron Sword in it. That leaves me wondering what other quests have bonus rewards like that that aren't listed on this site's quest page. I don't think anything new has been added to that page since it went up. I don't know who's in charge of keeping those pages updated, but I would greatly appreciate if they could go back, clean the subquest page up, and add missing information.