2 could be done if they took the concept of custom lineages and then gave them some generic options that could be flavored to make mixed species. For example, you could take darkvision, fey ancestry and resistance to fire and say you are half-elf/half-red dragonborn, or even half-hobgoblin/half-infernal tiefling. You won't get the cooler unique abilities of most species, but being able to pick some useful generic ones (fly/swim/climb speed, breathe water, resistance to an element, fey ancestry, relentless endurance, darkvision, bonus skill, or a bonus spell) might allow you to make something that resembles a hybrid.