Is it possible that you recreate the start menu of Windows 10 Build 9878? And even for Windows 8? I Really enjoy using Start8 ... but since i saw the Windows 10 start menu of Builld 9878 .. i want nothing else.. But the new start menu of Windows 10 Build 9926 does not have the same features and is terrible to use because the left side was replaced by "most used" ...
This is the perfect "Modern UI" start menu... and if you add the possibility to create folders in All Apps and to modify that section i think many will agree and you have a compelling product exactly as you had with Windows 8 and Start8 
