Fair enough 
May I suggest creating an object called like with two text fields. One for the unique ID of the object being liked and one for the user who liked it.
Yes you would have to do a search but it may be faster than the alternative which is to have those objects with lists of texts slowing down the page.
You could do one search for all of the likes that contain the current user and have that hidden in a repeating group placed in a popup that you never open (call it “var likes”). And then condition the object’s like icon’s visibility to be visible when the hidden rg contains the object’s unique id. The search will be faster because this like object will have only two text fields and nothing else. It would be a “light” object.
Indirectly linked dB models are usually more scalable