If we were several months into the introduction of the x36 units, that might have been a feasible option, as was done with the headphone jack problem on the 536. But we are now 20 or so months into x36 production, and I don't see your solution as being practical at this point.
So if your solution involves producing and handing out brand new units to potentially thousands of customers in return for their 18+ month old radios, and then refurbishing those old units for sale at reduced prices, I would have to brush up on my Japanese expletives to give you the answer you would likely get from them.
But we may be putting the proverbial cart in front of the horse here--- as far as I am aware, no workable solution has yet been finalized for either the RTC or the dimming issue. When a solution is reached and tested, only then can some process be put into place that would provide rapid turn-around of the customer's own units. I do have several ideas on how that can be accomplished--- I've seen this done in similar situations, but right now let's wait to see if they've actually come up with a solution to the electronics issues first.
And just to thrown into the mix, the fact that us x36 owners are also waiting for completion of those promised features which have yet to fully materialize.