I have a script with 250 MB of fileinstall data, when i compile it the file size reduces to 150 MB, even i select "Lowest" option on AutoIt3Wrapper. I don't want any compression, not "Lowest". reasons compression increases compiling time so much, i don't need compiling and when executable file is created, when i use thirdy party program like WinRAR, 7zip existing compression cause them worse compressing. Because compression softwares does not understand each others algoritm (not always but generally), one software mixes the data blocks and other cannot compress even it would able to. When you use extra compression metod it doesn't work, they overlap, even it may unexpectedly increase file size. It's always best to use only one and best one.
For example
First 7zip compression, then compiling script with highest compression option 250 MB -> 50 MB -> 51 MB
First compiling script with highest compression option, then 7zip compression 250 MB -> 150 MB -> 151 MB
If i use the lowest option, the result does not change when other program used. Because compression software cannot do anything anymore.
First 7zip compression, then compiling script with lowest compression option 250 MB -> 50 MB -> 51 MB
First compiling script with lowest compression option, then 7zip compression 250 MB -> 200 MB -> 201 MB