Ya. I have been using a flash drive with only the very last past year tax file to be transferred and start working for years without failing.
At the end of efiling for the year, I just have to save two extra copy to two portable drive where all my past tax files are kept just incase one died.
Now the flash drive I work on have would have this year and last year tax return files. I would delete last year and kept this year in the drive to be transferred next year.
It works fine. Even it get corrupted, I still have the backup. I let my family members use my laptop and they use their own flash drive to work on theirs.
