Why we can use only some extension on arduino uno?!


Hello there. I noticed that in mblock5 some add-ons are only used in arduino uno, but we use it in arduino nano because size is important in some projects, so we want all add-ons in arduino uno to be used in arduino nano.
And I want transfer mblock3 extension to mblock 5
(it is translated by google translate so may be some eror)