_cache of template-function

I have a small question about the template function (webix UI v.8.1.0 l.2491-2667)
Does it make sense to cache functions for which “str” has been changed during the function(l.2656,2660).

If I understand correctly, this makes no sense. Such functions will not be used from the cache, and they will remain in memory and will not be cleared by the GC.