Can I add another TL-WPA8631P to my existing TL-WPA8631P KIT, increasing the number to 2 extenders plus powerline and increase the size of the one mesh area?

Hi, I am having this issue with the Archer MR600 V2 model. The max speed I can get is 100mb/s download. I have access to 4 bands B1, B3, B20 and B28. Attempting any different combination Iof these ban