You can go further than the limit of ~16000 by bringing up the % in the corresponding cell in the F trim table, and applying trims.
It's a workaround. But you can't touch the cell in the main F1 F2 F3 table then or it'll jump back to ~16000.
Re P1614 fault code and flashing engine light, this is what happens when you try to load a map that is not suitable for your ECU.
I see you have the map above named "...based on 20355", but unfortunately you've actually used map 20773 as the base!!!
Is your Roadster a 2010 - (March) 2013?
If so then 20355 is a compatible map, but 20773 is for March '13 onwards Roadsters. VIN ending 574813 was the changeover.
I wouldn't tear my hair out yet though, with TuneECU you can "copy table" from your draft map, and simply paste it into the corresponding table in a compatible (say 20355) map.