It seems like a missed opportunity that the Enderflu effect has nothing to do with teleportation. It also seems strange that it can be cured by something as common as Chorus fruit. I'm guessing that feature was only added so player's aren't completely screwed if they don't have milk on them. But with this change, you wouldn't need that. You just can't teleport before the timer runs out. Or if you do, you take a lot of damage and then have to fight the newly spawned Enderiophages. (To be clear, they spawn at the location you teleport to, not from.) This includes using gateways, and even exiting the end through the portal. This puts it more along the lines of the Bad Omen effect; getting the effect isn't necessarily life ruining... as long as you don't put yourself in the situation that would proc its real effect.

Oh and, as a fun little easter egg, if you have the Enderflu and teleport with an ender pearl, and it just so happens to spawn an Endermite, the effect will proc on the Endermite instead of on you, allowing you to get off scott-free. The Endermite won't be so happy about it though...