If the Steam account was fresh then you would just disable cross-save and use that. With that said, realistically with the account unlinking change preventing platform accounts except Twitch from being unlinked from a Bungie profile - you would be better off keeping your Xbox account as your primary for cross-save; you would also be saving yourself the headache of the /join and /invite commands potentially breaking meaning players cant use them to join/invite you due to the way Bungie looks up player accounts. You have some progress on the account Exotic unlock wise, and the account was previously used in the past (2022) for running content. Edge of Fate did a bunch of system reworks that meant everyone was basically replacing their gear anyways, so you aren't at too much of a disadvantage if you were to just continue onwards besides the Edge of Fate Portal gear not having a fixed source (excluding Hawthorne because its RNG and might be bugged) that you can obtain higher-tier versions of like Mint Retrograde.