I never got much better than terrible left handed. One thing, the few shots on a nine foot table that can't be reached easily right handed are usually very simple left handed shots. Fifty pounds ago shooting behind my back was fairly easy and I very very rarely missed these shots.
A couple things to work around shooting left handed now that I don't bend as well with a few disks fused, I just bridge normally but bring my grip hand across the front of my body. The stick is in the same position as a left handed shot but the stroke is with the right hand.
Something else that works is to bend across the table from the other side, put the bridge hand and grip over my head and shoot. Sounds far more awkward than it is. Both eyes are working and again it is rare to miss.
I am not huge at 6'-2" but there isn't much of a table I can't reach right handed. A six inch extension would reduce that even more. However I have found these unconventional shots to work fine.
Keith was shooting a match, semi or final, with Efren. Match ball he swapped hands so effortlessly that few noticed it. I forget what it was, a televised match and it was on youtube the last I knew.
Hu