Using a brand new, vanillesque, installation of 1.12, I saw that loading time were very loosely related to the amount of minerals loaded. It can be a feature, because realistically you might need most of your time not loading minerals, but preparing for the transfer.
For example without any modifier, loading 1 sorium takes 11h35 mn, for a freighter with one shuttle bay, on Earth with a spaceport.
Loading 250 takes more than 2 days.
Now there are two issues with that though ... The first one is that it cripples the interest of "Load Mineral Type" where you desire to load a bit of each. It takes almost one month to load 250 of each minerals ...
The 2nd problem is that some orders act as if they bundle 10 orders in one. Because this is what load/unload to reserve levels do, it takes only 2 days to balance the amount across the 10 minerals!
I would not be adverse
if the time it takes was a bit more tied to the actual amount, that would help "Load Mineral Type". And also reduces the discrepancy with Load/unload to reserve levels.
