BUT what is the problem that's being solved? I guess the problem IS the ridiculousness of the yo-yo.
Yo-yo healing:
1) PC doesn't get healed during combat.
2) PC gets mauled, but stays in the same place to keep fighting.
3) Surprisingly, PC dies.
4) PC's ally uses a cure spell to return the PC to consciousness.
5) NPC, who hasn't moved more than 1 round away from fallen PC, walks over and knocks PC to 0 HP again.
We'll assume this trend continues in a cycle.
There are several solutions provided/available in unmodded 5e, which a lot of posters (seemingly) don't want to accept:
1) Heal your allies before they die.
2) Try not standing underneath an ogre-mage club.
3) Step 3 is warranted/appropriate.
4) Maybe wait until the opponent has moved out of attack range/draw opponent out of attack range?
5) NPC confirms the kill before the healer heals, or NPC attacks the healer.
Yo-yo healing is only ridiculous if you ignore the simple solutions to it. But as one poster said, "attack attack attack." If that's your plan - expect logical consequences.
@fluffybunbunkittens Wanna flee faster opponents? Get a horse. Unicorn. Pegasus. Owlbear. It's D&D - get creative.