SCY,
As mentioned earlier, the processes are different & MIM is not traditionally referred to as "sintered".
If you want to blur the lines in discussing it, that's up to you.
As far as altering the cast trigger goes, I've had that done on three GPs.
The cast triggers came with sharp edges on the rear & I had those removed along with rounding the faces to meet my preferences.
I'll eventually have the same work done on two others.
The newer MIM triggers don't need either work, they have no sharp edges behind & they're more rounded up front.
Fine as they come.
At least- on this newest one here, if its representative. This is the first GP I've had with a MIM trigger.
So far, all MIM Ruger GP & SP triggers I have do not have the sharp edges, at the very least.
The SP MIM trigger isn't quite as rounded on its face, but I see no need to alter either of my two SPs that have the MIM trigger.
Denis