@squig I don’t know if you have seen this topic. It covers a lot of different mantle control methods.
Maybe you could have a look and comment on the control i found.
https://www.aliexpress.com/item/4000414358347.html?spm=a2g0o.productlist.0.0.674b30f68k9CPy&algo_pvid=dd62ee6d-e378-4656-be82-cd89e680efa4&algo_expid=dd62ee6d-e378-4656-be82-cd89e680efa4-0&btsid=0b0a0ad815984655020087801ed1d4&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
I agree with you that a heating element can be controlled by a variac so long as it can provide enough current.
@spdking ( i’m not trying to cause an argument or anything, I don’t have a lot of money so have to be a cheapskate lol )