Some MPS modules could emit particles like smoke and bubbles depending on the use and situation.
If you are flying, the jetpack would emit smoke trails according to the thrust (more thrust = more particles) and torso angle (sneaking, Smart Moving).
If you are underwater, bubbles instead of smoke. Also the Water Electrolyzer could emit a small stream of bubbles upward every time it runs (you can hear the sound in the current version).
As example, Mekanism jetpack emits jet trails (image), except that is a bit too much.
EDIT:
Leaf blower module could also emit "white" smoke particles as if it was air jet.
Totally aesthetics. Low priority.
Some MPS modules could emit particles like smoke and bubbles depending on the use and situation.
If you are flying, the jetpack would emit smoke trails according to the thrust (more thrust = more particles) and torso angle (sneaking, Smart Moving).
(post)
If you are underwater, bubbles instead of smoke. Also the Water Electrolyzer could emit a small stream of bubbles upward every time it runs (you can hear the sound in the current version).
As example, Mekanism jetpack emits jet trails (image), except that is a bit too much.
EDIT:
Leaf blower module could also emit "white" smoke particles as if it was air jet.