Yes, that section is fitting and interesting. It is the production-side view. I think I was more motivated by the comments envisioning an abundance of cheap gold, which seems not in any way near or even possible, even with this approach as cool and baffling as it is.

I don't think that it is of much use as waste disposal because again, it can only remove 10%, i.e., an insignificant amount. If it were even mined because of this, then more mercury waste would be produced than before, but increased mining would probably be many decades or centuries in the future, as long as there is still waste to reuse.

So, how long would the current midterm stockpile of 1400 t for 198Hg for the next 10 years last? At 5 t per 1 GW per year, i.e., 5 t per 8.76 TWh, and a current global electricity generation of ~30 PWh, replacing all energy production with fusion would be able to transmute 3400 t 198Hg per year, over twice the stockpile. Of course, there would be a myriad of other bottlenecks long before that, but consuming all the existing stockpile seems feasible in human time spans.

I am honestly impressed by the amount of transmutation that is possible with fusion. And it is a lucky coincidence that the half-life is only dozens of hours for the middle product. I never thought of that process or would have guessed grams of production instead of tons, probably because of the association with existing particle accelerators. It is quite amazing, but also presumably still decades off into the future.