No need to buy anything.
As I do not know what set you have a bit hard to comment but if I do anything it's very minor e.g. thin plastic cut from a milk bottle.
Local Beach: New Brighton near Liverpool. Open sea with big low tide deep lagoon and regular at Rhosneigr and Newbrough on Anglesey
Favorite Beaches: New Brighton, Rhosneigr, Fleetwood, Newbrough, Blackrock sands lake Como (Italy) El Medano
Style: kite foiler since 2017 Ttip since 2000
Gear: My rule to gear choice is "IF IT DONT BOOST ITS NO USE" Groove Skates 110cm 2022 editions kraken mast systems 103k and 93k. Kraken fuse 703k Duotone SLS Evo's -- 11mtr/9mtr/7mtr/6mtr/ 4mtr RRD. Duotone 2022 click bars x2,my own custom made lines fitted, (modified lines now available for the flite99 shod duotone bars)
Bar lines made up to any length in a choice of strengths, power lines, trim lines, pigtails, leader lines, bridal lines, elasticated lines, I make and fit them all, free fit and tune service, quick turnaround,drop me a message, find me on messenger, Colin Moore.
You can also shim the mast to fuse, which is a better solution as it does not mess with the stab to wing angle of attack. If you shim the stab you are creating the potential for a less smooth ride and reduced glide because you are countering the lift with the flight of the wings and then countering that with your CG.
The following method leaves the AOA of the wing combination the same but moves your CG in the direction you need to feel balanced.
In aircraft terms, shimming the stabilizer is like applying a bit of up elevator through the controls, then moving a bunch of passengers forward to counter that lift and keep the nose down. There is disruption to the airflow.
This method is like establishing trimmed flight for the wings and stabilizer in their neutral state (smooth), then moving passengers around to find the right center of gravity.