Several members here have said it does reactivate the screen. This from member Pappy13 in a thread with that specific question: "mine does re-set the windscreen on my 2013 GT." I'd say splash away ("splash the cash" is a first-rate phrase!).
The windscreen function often dies when the battery is disconnected. Although I replaced my battery last year, fully expecting it would require a trip to the dealer to reboot the ECU and get the windscreen working again, but the screen worked perfectly with the new battery, even after the disconnection. I made the battery swap as fast as possible, from old to new connected in under thirty seconds, so maybe that had something to do with it.
I considered GS911. Ended up buying the MotoScan app. It doesn't reset the windscreen but does pretty much everything else I need, resets SERVICE alerts, reads and clears fault codes, displays performance data, integrates new TPMS sensors (aka Reifendruckcontrol or RDC).