Borrelia changes its outer surface proteins more than most bacteria which would lead me to believe that it does not sequester heavy metals. It has been shown that it does sequester manganese. I guess manganese is a metal and it is relatively heavy and is toxic in too high a concentration.
With that said, I do feel that heavy metals are a major issue with many Lyme patients. This is not necessarily because Borrelia binds heavy metals, but because other pathogens present do bind metals. Herxes are often metal or toxin related.
www.pnas.org/content/106/9/3449.short