End if

[Darkstar]

I've been seriously thinking in this, and the only solution I've come up with is that implementing "Single line" IFs will be exclusive (that is, when enable, END IF will be disabled).

Yes, I agree. All things considered then this is the ONLY viable solution in my view.

Also, it might also be sensible to enable Single Line IFs in Compat only mode along with the old versions of PLOT/DRAW and the READ/RESTORE/DATA
commands.

Or do seperate directives like: #Pragma CompatPrimitives and #Pragma CompatSingleIFs and #Pragma CompatDATALists.
Then the user can control what to rewrite and whatnot, and the CompatPrimitives (PLOT etc) is then coupled with the --sinclair option.
Then you can turn it all on at once by using #Pragma CompatOriginalBASIC and that makes four #Pragma(s) in total. No need to specify
"CompatOriginalZXBASIC" because that is specified implicitly with the --sinclair option.

Of course, in SingleIFs mode with END IF disabled then the current format is disabled but that is OK because I suspect that the orginal BASIC dialog
in the other machines do not support it.