Actually I have never done a digital transfer. This is new to me,
In 2005 I pulled my certificate of 1,000,000 shares in one company, but I still have 30000 shares of the same company, in my Etrade account, just waiting, and it only cost me $20 back then, and I did it by phone. Call me a dinosaur, but this digital transfer sounds like a viable venue to transfer some of the shares of several companies I own and I would do only a partial transfer.
For example I have 100,000 shares in XYZ Stock, I would do a transfer of 50,000 shares in case the stock does strike up, then at least I can trade half of my shares and if it does take off, I will have them transferred back to my Etrade account.