It turns out the formula without a helper column was straight forward. I must be better rested this morning. The IFERROR part is just to deal with the #Value error you get trying to rank a blank.

=IFERROR(RANK(IF($A$2>A2,"",C2),$D$2:$D$11,0),"")

Scratch the above. I had a bug in my test formula.

For your second question, TRIMMEAN would work to eliminate the top and bottom. I haven't used it, but it excludes the high and low percentage. To make the percentage exclude only one item at the time and bottom is straight forward.

=TRIMMEAN($A$2:$A$11,1/COUNT($A$2:$A$11))

However, that's not what you asked for!

AVERAGEIFS will get you almost what you want. One of conditions could be "<>"&LARGE($A$2:$A$11,1). The other condition would be the same, but excluding SMALL. Unfortunately, I believe this will exclude ties if you have two identical results at either the top or bottom.

I think you have to use a helper column to rank your results to make this work. Then it would be easy to exclude your outliers. This RANK helper column would just rank all results regardless of location or hybrid. Let your AVERAGEIFS deal with that part.

There are ways to set up the ranking so that ties are broken. Even ties in the middle of your ranges are critical because a middle result in your full data might still be a high or low in your specific test situation. I'd have to look up an example of something I've used in the past if this makes sense for your needs.