We categorized any abort prior to 80 knots as a 'low speed abort'. A low speed abort was considered pretty much a nothing event - I don't think the safety people even tracked low speed aborts.
It's only above 80 knots that things really start to get interesting - before 80 knots, it's considered OK to abort if you even suspect something is not right.
I used to see regular reports of low speed aborts due to 'uneven' engine acceleration - it was rare that anything was actually wrong - most of the time it was something as simple as not having both/all throttles at idle prior to pushing for takeoff. The engine(s) not at idle got a bit of a head start and would accel more rapidly - resulting in the abort.