I've literally never gone away from 3 Urborg in this version of the deck. Like, here's the change log:

June 2016: started playing the deck. After 1st challenge, -3 Into the North +3 Expedition Map
(various Miracles sideboard changes, maindeck remains unchanged for ever)
Top ban April 2017: -3 Not of This World +3 Sylvan Safekeeper, fix sideboard to 4 storm hate, 3 Library, 2 surgical, 1 Needle, 1 Karakas, 4 Decay
(various alterations of 4 Sphere vs 4 Mindbreak Trap, maindeck unchanged)
January 2018: fixed sideboard to 2 Sphere 2 Thorn, -1 Petal to +1 Dryad Arbor maindeck