I don't think it is a good idea to make any changes to bricks in the normal game or change an escalation for a custom mission. We have the tools for custom bricks now, so you can either add the existing TEMP as new raw resource or maybe even create a new entity from scratch containing just the swap. Then add that to the content pack and register with a framework.json.
Unrelated suggestion: I'd like to see your Additional Missions content pack split up into more logical content packs with better names. You did rename your mod after all!
No idea what happened to the Lee Hong mission, but that one is completely wrong in the version I last uploaded: as flashback it lacks a subtype, so it is displayed as seasonal. Also, it would need a translated title. If I changed that one on accident while mass-editing other things I'm sorry! I will upload a fix just for that soon.
Regarding making items available, I did think about it but don't have a clear opinion yet. It would be easy to add all non-unlockable items to loadout with a framework mod, but IOI would probably not like that and it would be a mess in the item menu. A more selective approach as a content pack could work, but the question is which items to include. Feel free to propose something in the private alpha forum.