Here's a general question - how do you know that your T4 levels are off? Do you have particular tell-tale signs to suggest you're too high or too low?
Yes and no. I know when i'm going more hypo because when i run my legs are "dead" and i feel like it's the end of the run at the start. Also i feel more tired and like i'm never fully "alert" or "awake" - like i'm sleep deprived even when i'm not. My eyes get a bit puffy and my hair begins to thin slightly at my temples (first place it goes on me). My weight creeps up (but by a kg or 2, nothing dramatic).

BUT me feeling that way doesn't necessarily mean my fT4 will show up low on a BT. As you know, it can take a month for TSH levels to change in response to T4 dose adjustment, and it can take up to 3 months for the levels to be stable enough to know if the new dose is doing the job. I tend to feel illest around January and July, and i assume that this is when my Hashi's is most active due possibly to other viruses around at those times which activate the autoimmune response.

Bx