How to keep protein warm while making pan sauce?

Hey all - probably a silly question, but I've run into this problem a few times now and not sure how best to solve it :P I recently got a stainless steel pan and I've been making some protein + pasta sauce dishes, but my protein always ends up cold by the time the sauce is done.

Last night I made chicken and sausage alfredo. My pan is a bit small and I was doing 4 chicken thighs with a good bit of sliced cajun sausage, so I cooked 3 thighs in the first batch, 1 thigh + some sausage in the second batch, and finally the rest of the sausage in the third batch. In between each batch I just put the meat on a plate and set it in the microwave, hoping it would retain some heat.

Then I deglazed the pan with some pasta water, made my alfredo sauce, and sliced my chicken while the sauce was thickening. By the time it all came together, the pasta and sauce were hot, but the chicken and sausage were already pretty cold.

In other dishes, I can see this not being an issue - e.g. if I'm only cooking a steak or two, I could make a pan sauce while the steak rests, and everything should be fine temp-wise when it all comes together. But how should I handle this when I have to cook protein in multiple batches, or when the pan sauce takes longer to come together (like waiting for an alfredo sauce to thicken up)? I thought about putting the oven at a low temp and putting everything in there, but I was using the oven to bake some bread at the same time at 400 F, and I didn't want to overcook the protein.

Bonus question - during my cook last night, the fond on the pan started burning a bit more than I would've liked as I cooked all 3 batches. Should I deglaze the pan in between batches?

Thanks in advance!