So far, this has not happened to me. My old Strat (had that for 23 years), the Jackson Elite (had this for 2 years), the Yamaha acoustic (had that for 46 years) etc. It might do at some stage, who knows.
My working guitars change position as favourites all the time. So I would have to be pretty sure when losing one of those!
I wondered about upgrading to a Pod HD500, but I wont get rid of the 400. Its all set up nicely as part of my rig now. I would just keep it as a gigging tool. What ever other line 6 processor I might get would be for studio & home use.
I should be able to import the custom patches into a new sp. If not, I know how to reconstruct them.
Odd that you cant change string gauges on variax. Lucky for me I use 10-46 on electrics anyway. The only exception being the Hofner which has 11-65 flatwounds. I know what you mean about swapping gauges though. I used the Hofner yesterday evening for a couple of hours. When I picked up the LP afterwards I was forcing the strings hard down onto the fingerboard for 10 minutes & losing intonation because of it.