you are definitely wrong.
every witness should input the feed price without any dependence from other witness or median price.
this is what the meaning of "witness".
here is a possible result when follow your suggest:
suppose there are 3 witness, a gives price 0.059USD, b gives 0.06 USD, c gives 0.061 USD
when the price rise, b change to 0.061, c change to 0.062, a get a new price at 0.06, so he don't need to update feed price.
when b and c goes to 0.062, 0.063, a still keep unchange.
...
when b and c goes to 0.1, 0.101, a still keep unchange.
now b and c got a chance to control median price between 0.059 to 0.1.
for 21 witness, when there are 11 witness always get a little bit higher price, while other 10 always get a little bit lower, this could happen too.
Is that were we are trying to go with this? Provide frequent up to a minute feeds?
*Publishing* a feed every 2 minutes is normally not required.
*Checking* the feed often is a good idea though. Technically you need to publish only if
a) your feed is about to expire, or
b) if the new feed price would change your position relative to the median (i. e. old price was below median and new price is above, or vice versa), or
c) your feed price *is* the median
You may want to publish more often than that to avoid being accused of neglecting your duties. :-/