I think one spot where it is dicey is, obj[dynamic_property] = /* … */; … for which you must, rather unfortunately, be aware of prototypes. (And if you can

I think one spot where it is dicey is, obj[dynamic_property] = /* … */; … for which you must, rather unfortunately, be aware of prototypes. (And if you can use Map, you probably should… it avoids the JS footgun here.)