T3 Cycle Questions

So about a year ago I had my thyroid totally removed due to a few nodules that were supposedly canceroud but the post surgery biopsy came back negative. So I am currently taking 250mcg of t4 daily and 500mcg on Sunday as my replacement dose. I’ve seen a few threads regarding low dose t3 cycle over an extended period of time.

My question is seeing as I don’t have to worry about destroying my thyroid what would be a safe dose to run long term without causing a huge loss in muscle mass? Should I stick with a 12.5mcg daily dose or increase it? I’m currently running an eca stack only. This will be without the aid of aas. Let me know what you guys think.