Note: This is the second part of a question. The first part can be found here.
Incorporating some feedback from the answers I got to the question above, I have made a few changes.
Here is some background. So, 200 million years before the present day on my planet, a massive asteroid rich in indium and gallium hits my planet. Due to wind currents and stuff like that, the indium and gallium spread all over the planet. However, indium and gallium compounds are range from toxic to possible carcinogens and life starts to have problems.
However, an extremophile adapts to this problem and develops a symbiotic relationship with almost all life.
Basically here's what they do:
$$FeIn_2S_4 + enzyme \rightarrow In_2 + other \, stuff$$ $$CuGaS_2 + enzyme \rightarrow Ga + other \, stuff$$
Once they have the plain indium and gallium, they combine it with tin to create some sort of galinstan like alloy, which is then excreted. From my understanding, galinstan is totally non-toxic. However, it is synthetic. Would this work? If not, can you suggest other mechanisms?
Remember, since the gallium and indium arrived from an asteroid, it isn't enough to say that they will just adapt over billions of years. The organisms have to cope with the gallium and indium somehow.