My MIG skills far exceed my TIG skills (I'll be doing something about that soon)..
I have no issue using MIG rather than TIG for work like this as long as the heat along with wire size and speed are all dialed in - as it appears you've done..
I have no issue using MIG rather than TIG for work like this as long as the heat along with wire size and speed are all dialed in - as it appears you've done..