For reference, here is a rather epic thread on persistent spot instances by @slavivanov
I also worked out my own solution which I describe in a medium post Not sure how it compares to the solution by @slavivanov but it allows me to spin up a spot instance of my choice issuing a single command from terminal on my local machine. The way this works is that you have a volume that is getting attached while you provision the machine and that gets detached at tear down so you don’t lose your work.
All we need to get this to work for part 1 v2 is a setup script to replace the one provided for part 1 v1. @jeremy mentioned in one of the other threads that maybe he will be releasing one - which would be great as I would prefer to use something solid - and if not I will modify the script from part 1 v1. Have something rudimentary here but IIRC there were some issues with it.