We have internal front end libraries that works with JSP only. From the sounds of SPI, I thought that I could use JSP and our internal libraries instead of FreeMarker templates. Also because our JSP login screen is almost ready it wouldn’t take much time
to just deploy it (that’s what I thought).
What are you actually trying to achieve? We mainly support modifying the FreeMarker templates and stylesheets. Beyond that you may in theory be able to re-implement it all to replace FreeMarker with something else, but I don't see why you would
want to and it would be a significant amount of work, and also maintenance.