A move from Harbeth to... Wilson?

I have had one experience with a Wilson speaker, so I am far from an expert, but I will give you my experience.   I would demo the speaker, preferably in your setup, but if not, then at a dealer.  I would not buy them without listening to them first.

This is my experience with the Wilson Watt Puppy.   The dealer was extremely nice and did a tour of the system the Watt Puppies were connected to, showed me how to adjust the Watch Dog subwoofer, pointed at a huge collection of CD's and said, "You can stay as long as you want, if you have questions, come and get me," and then left the demo room.

A friend and I spent the next two hours listening to the speakers and playing around with different adjustments on the Watch Dog.  There was a seat between the two speakers and if you were in that chair, there was the most three dimensional, accurate, pleasant sound I've ever experienced from a music system.  HOWEVER, if you moved left or right, changed seating height the sound stage became flat and no different than fifty other speakers I've heard.

The Watt Puppy speakers were extremely accurate, but also, extremely directional with a very, very small soundstage.  Whether that's the case with the Wilson speakers you're considering is unknown, but you should listen to them very carefully before buying them.

OP: check out the room size here:
https://www.whatsbestforum.com/threads/harbeth-monitor-40-2.25222/

your Harbeth’s have that Rogers, Spendor, Stirling Broadcast (Proac ATC?) BBC monitor lineage and dna.
dare I say an apples and oranges comparison discussion in regards to Wilson?
I would move up to the big box Harbeth 40 as others have suggested and maybe treat yourself to an additional upgrade elsewhere in your system.
you will be after all... saving several thousand delore’s on that automotive paint finish🤗

Haven't heard the Sabrinas, but I'm a bit cautious as they are the latest generation of what started as the Watt/Puppies none of which ever captivated me. Problem is that anything above that in the Wilson line escalated price very significantly. Best to do some auditioning yourself ad think about it.

(FWIW I have loved several models of larger Wilsons and have a pair of Maxx 2 in one of my systems - the Alexx are the modern speaker in that niche today).

I think the Vienna Acoustics with their soft dome tweeter would sound less harsh.  I noticed they had a lot of bass and sounded best when listening to classical.  I did think they sounded great and I think you would get less fatigued listening to them.  I think the Wilson's sounded a bit harsh in the highs.  However, I needed to listen to them for a couple hours to determine what I was hearing.  I thought the Motion 60 Martin Logins sounded great, but when I went back and listened to them for a couple hours the ribbon tweeters seemed a bit harsh.