now this maximized window must not cut off ok/cancel buttons too
The Devil is in the details - works as expected.
Speaking of details, in the description of the "Write result of virtual tag expression..." example preset, you put in the (English) description: "...If you want to pass a string to a function as is, you must put it in DOUBLE quotes."
Due to the vagaries of English, the _"_ symbol is actually called "double quotes", while the _'_ apostrophe symbol is "single quote". So, when you say "put it in double quotes" you're actually just saying surround it in a
single set of quotation marks, which is obviously the wrong syntax.
So, instead of "DOUBLE QUOTES" you should probably say something like "put it in two sets of double-quotes", or "double-double quotes", or even "quadruple quotes", though the last two are neither colloquially correct or properly descriptive.
I think originally you had an actual \@eval example in the description which showed the proper syntax, not just in the <Custom Text 1> slot, which can be overwritten by the user if they modify that text. Including the example in the description was the simplest thing.
So, yeah, that's the long way of describing a silly detail. Just a devilish suggestion. God knows why English became the de facto internet standard - almost anything else would have probably been better.