I’ve only seen CURSES in src/CMakeLists.txt. Curses build is built if TILES isn’t defined, explicitly invoking make CURSES=1 will not do anything.
Pretty sure TILES implies SDLTILES. If this is the case, they could probably be merged.
Running a simple search+replace would probably be enough.
Still, SDLTILES is an internal flag, not listed in the makefile or compiling guides, so it’s relatively low priority.