There is a "FAA minimum, then there is suggested".

You think you are good, current and safe, maybe a single flight to get the pencil whip is OK.
Yes, maybe you are, I have no clue.

As an ex CFIG, I will chat with candidate, look at logbook, then maybe throw "stupid crap" at them for a review.
It is considered a learning experience. Doing things outside of your normal. Some may call it sadistic, maybe it is.
Then again, having someone push your limits (ummmm.....within some reason) is a good thing since you may have not had to deal with unusual in quite a while.

Not saying you are unsafe, have bad habits, or could use a second opinion.
Just saying that getting the "biennial" check mark is not the real goal, the goal is finding things that may need a nudge.
Some fail upfront, some need more than one flight to test things.

My opinion, FWIW, would you rather have a good biennial just before an incident, or a pencil whip? The FAA may not be happy with the later.
When I do mine, I have a hefty yardstick to be measured against. Thus far, I have passed. And yes, I learn things at times.

As an aside, I have missed some of the recent "glider related" wings sessions, I have the new one listed as an event.
I used to do them (20+ years ago) when it was all SEL power and up.

These can also help edumacate power guys. A couple months ago in the AOPA magazine, there was a letter/article that talked about what to do on takeoff to help with a power failure. Most glider pilots would say, "well, duh.....". But different perspective.