Help, Using and Free Bpls from Memory / Dlls liky system

Hi, in order to don't increase exe size and optimize resources
when executing my applications i put certain forms into DLLs,
then in the button that calls this forms i load the library, call
the function that shows me the formulary and after closing it
i free the library. With this system when i push the button then
exe size in memory increases (dll loaded) but when i exit from
the dll-formulay and free the library exe returns to its current
use of memory.

I'm trying to replace this system using BPLs ant not DLLs,
when i load the formulary into the package from my application
then exe increases the memory usage (like dlls) but when i free
the formulay the exe doens't returns to its original size. (Seems
that continues with the BPL loaded)

How can i return to its original size? How can i free all the amount
of mem. used by the package and that are not in use in the app.?

Can i free a BPL from the application?

The objective is have the same characteristics of memory usage of
a dll (only increasing when are in use and loaded)

Thanks for all.