Spent some time with Echannelizer this morning - have to admit never used the picons creation on Echannelizer.
So a couple of things........
Although you can specify where to save/create Picons on the PC, I cannot find anywhere to specify where they are on the Receiver, and Echannelizer cannot locate them by default on my receivers - my Picons are on HDD or usb, not /usr/share .

If I replace Picons, I have always stopped the box (using putty telnet) with init 4, then copied the picons to the receiver ... which you can do as you know the store location in Echannelizer, and then init 3 to restart the receiver.........you could also try using Echannelizer to save only the Picons to the receiver while stopped(init 4) and then init 3.

Its probably not the automatic system you would like, using one piece of software, but the safest ......