I tried, I really did, but I couldn't manage.
On the other hand, the principle is fantastic . . . so
I already sold the A7r. Now my A7 kit is on ebay . . . but
The 55 f1.8 and the 24-70 zoom are snuggled up in my lens cabinet, waiting for the 36mp camera with EFC and proper weather sealing and no shutter lag.
Then I'll be back!
all the best