slightly cursed but we save 160 bytes

include/LCDDisplay.hpp

@@ -9,7 +9,7 @@
 class LCDDisplay {
    private:
     uint8_t _lcd;
-    char linebuf[4][40];
+    char writebuf[168];                // 4x40 chars + 2x4 setcursor commands
     void writeStr(std::string str);                     // do not use
     void writeLines(std::array<std::string, 4> lines);  // do not use