Terrain Size throws scaling off?

So I made the terrain width and length 5,000 rather than 500 and find it nearly impossible to place a cube on the map or get a close enough view to be precise. Is the problem how big i made the map? Should i just attach terrains together instead of one massive one?

Its preferable to have mulitple terrains stitched together, so that you can then eventualy hide them and show them for performance reasons. Also working with big terrains is causing issues with painting heights, because the brush gets small.

If you would want some easier process how to work on bigger area for your project, check out this plugin i made for my game, since i am working on an open world game and using Unity’s system was just too much of a headache.

Terrain Toolbox