There is obviously another way to compile from a command line with metaeditor.exe itself which turns out to include the compiler.
One can notice that terminal.exe launches metaeditor.exe at startup to compile not already compiled .mq4 files. The command line looks like:
<path>metaeditor.exe /compile:<path>code.mq4 /inc:<path>\MQL5 /flg:2 /stop:value
what are those /inc, /flg and /stop parameters for?
Are there other parameters?