Should I use shim on rear wheel to correct -0.25 degree toe out

Hi. I bought a used 2008 Aveo5 LS with 148,000 km and had new front lower control arms put in. After the control arms were replaced I put on brand new winter tires front and rear and had a four wheel alignment performed. Everything was within specified ranges except for the rear passenger side tire having a -0.25 degree toe which was out of factory tolerance. The rear driver side tires had -0.05 degree toe. Thrust angle is 0.30 degrees.
I was wanting feedback from the forum members as to whether I need to shim the rear passenger side to fix the toe so I don't have excessive tire wear or is the -0.25 degree toe nothing to worry about.

Off topic, I know I should post this in a different thread but since you are reading this, I also notice that my 2008 aveo5 has the plastic thermostat housing. Am I sitting on a part waiting to fail and should change it out for the aluminum one, or has the oem thermostat housing failure rate improved with the 2008 and newer versions of Aveo?
If I change it out I was thinking of using the Dorman repalcement #902-109. Does anyone have experience with that one good or bad?

Thanks for your thoughts.

I probably wouldn't worry about shimming the rear tire. Just rotate regularly and you will be fine. Yeah, that one will wear a bit faster, but I don't think its a huge deal.

If the thermostat has lasted this long, I'd keep rocking it.

Thanks so much for your expertise. I won't worry about the shim but will rotate regularly and monitor for tire wear. I took a closer look at the thermostat housing and saw that it was the 2 piece aluminum style. It must have either been installed a while ago as it was covered in dirt and grime and looked black like the previous oem housing upon first glance.