User blog comment:Aeinstein/Aein's Mod/@comment-3293097-20161002045557/@comment-25237422-20161002053317

look for "function qh" in the code, there should be something like "this.i=?" where ? is the length of the world map in pixels.

Also, look for "qh.prototype.b", in the same line of code there will be something like "V(this.t+4,-720,0):492ag&&(this.t=V(this.t-4,-720,0)", then, change both -720s to a smaller number (in my mod I changed to -1130), those will allow you to scroll the map further, and still in the same code, there will be ";-720>",13158600,5263440)", change the -720 to the same number you did in the previous codes (that will allow the ">>" thing in the map to appear as you scroll more into the new regions in the map)