Yes use 2 fingers for planned breaking (non emergency) with throttle blipping and 4 fingers for unplanned breaking (emergency).
The catch with this is, whatever you use for normal / non-emergency braking is exactly what will be used in an emergency situation. In a true emergency moment where instant braking is necessary, there is no time for the brain to think - there is only reaction.
This is where muscle-memory instantly takes over, and it's why MSF teaches new riders to cover the brake with all four fingers.
cbr250r has a wet clutch,, meaning that plates are bathed in oil,
which aside from specifics of friction effect of oil, means that
'slipping' the clutch [feeding the clutch into power uptake]
or 'feathering' it, taking a little clutch pressure away by lightly
and partly disengaging the clutch engagement, are not,
going to damage or wear out your clutch..
ditto when feathering the clutch momentarily thru a turn
when harmonising engine output with drive train speed
[preventing 'snatching' or loss of power to the road]
which results in - momentary - 'coasting' ie, not,
gliding thru a turn with the clutch pulled in,,
but using the clutch, as part of its purpose
and function of controlling power flow thru
your drivetrain and into the road...
[this does not mean, feathering for the sake of feathering,
or taking power from the drive train to coast, unnecessarily,
rather using motorcycle riding skills for better control]
simply riding in and with traffic including slow speed
[down to walking pace] riding will be improved and
made smoother when the clutch is also used as part of
your control skills.. relying on friction point in such
ongoing situations is ignoring a basic control mechanism,
the clutch, which is designed and exists for this and
other types of smooth control of power, acceleration
and speed, emphasis there on 'smooth'..
just responding,, in general i dont have any problems with corners or turns
never blipping the throttle while gear changing up or down..
usually, the appropriate speed revs and momentum for the corner
isnt a problem and are the norm, but sometimes due to other drivers
doing their things, or a car parked too close to a sharp corner,
or any of many possibilities, i find my continuum of gear, rpm
and drivetrain responses can be made smoother by feathering
the clutch a little,, thats all..
similar if exaggerated relationship might be such as
starting off on the flat in second, using throttle and clutch,
whereas without clutch drivetrain would snatch and be rough..
comments on wet clutch etc, relate mainly to members
expressing concerns about damaging their clutches
or abusing them in general riding techniques,
which wont happen with this hondas wet clutch..
any riding skills or techniques are simply sharing
for anyone interested, as i have been, for many
years of road riding on honda motorcycles..