Car has a maximum hitch weight of 140kg, load on the trailer (total 2650kg inc trailer) is currently adjusted to 97kg.
Add a bit more or about right?
Advice is to get close to the max nose weight for stable towing.
Also I think the ideal figure is 7% of the trailer weight, which would be 185kg. So you are running lighter than ideal.
Better to move weight at the back forwards towards the axle centre line, rather than add weight to the nose though.
Ideal nose weight is 5-7% so you could go for a bit more. 5% is 132kg so within your max although 7% would be over.
If you can adjust the towball height up and the trailer is twin axle, that would also increase nose weight.
OK cool, I'll move it forwards a bit.
Advice is to get close to the max nose weight for stable towing.
As above, 5-7% is the guideline. Max nose weight of the car results in squashed rear suspension which makes the ride poor and the seats need adjusting cos they are tilted back (in my car anyway).
Everything is much more pleasant with 55kg on (about 6% of load at a guess) than with 85kg on, which is the car's max.