-You can stand in the dire's fountain area, well within attack range. Since the fountain doesn have vision over you - it wont attack you. Perhaps give the fountain more (night)vision. Also the radient fountain always has vision over you. Its a bit inconsistance.

-The fountain's truesight range is less than its attack range. You can go inside the fountain area with shadowblade and be safe. Is this desirable? Twrs (in dota1 for sure) have 100 more truesight range than attack range. Tested this only @ radient side tho.