There are two separate issues here at hands:

1. 3/4 time signature. OpenMPT will always import MIDI files as 4/4 because supporting different or more than one time signature in MIDI import would add a lot complexity than I'm comfortable with to add.
2. Quantization: I guess it would make sense to add 24th, 48th and maybe 96th quantization to address your problem. But note that you can already choose any quantization amount you like by going to the Advanced Settings and setting the MidiImportQuantize option to the desired value. 96 seems a bit excessive for most files, maybe try 48 first.

Setting the value of MidiImportQuantize is what I needed.

I definitely need to work with pattern data that determines note information up to 1/96ths while running every row as a single tick.
I failed before to notice MidiImportQuantize in the value list; my bad, sorry.

Thank you so much for the response.

I have added 1/6th, 1/12th, 1/24th, 1/48th and 1/96th to the options for the next release.