I have quite a few. I am also a dev of a structure mod, if you would be interested in joining, let me know! We have no deadlines, and any builds you make on our server can either go in the mod or be kept for your datapacks! I would also be happy to contribute to this pack, even if you don't feel like joining the team. Prehaps a sunken outpost is up next?

Or you could even take a page from dungeon now loading (really good pack turned mod) and make a sort of shrine in the dungeon that takes items thrown onto it and converts them into a portal frame. The items needed for the conversion with the shrine could be noted in a written book, with possible ingredients being endstone, eyes of ender, and perhaps rarer items, like a nether star. This method instead of crafting A. makes the player need to find a stronghold to get end items so they can make the portal and not skip the stronghold B. also makes finding YOUR dungeon worth entering beyond loot even after they find a stronghold, and C. allows players to eventually make their own end portals down the line. I would suggest making the crafted item breakable though, probably through right-click, though it would not drop. Otherwise, griefers will cause problems. I hope this made sense.