Rumor is that the Garmin charting chip will not transfer to another device -- some sort of ID is encoded when you load/run it.
I have always found that the best answers will come from a full service local marine electronics store. Sometimes even they have to make threatening noises to a manufacturer to get a good answer.... Garmin is not tops on the list for product support, either.
To give the electronics devil his due, Garmin pays a price for their "vertical charting integration" and has a constant struggle to reduce piracy and duplication of their charting software.
In sharp contrast (bad pun) my laptop computer has low-cost nav software and a big scren, but cannot live outside in the sun and rain like a dedicated chartplotter -- oh well, at least my charts are free from NOAA and always up to date.