Resin alone essentially has no structural strength. The tips of boards are also notoriously weak, due to the fact that they are typically one area that has a poor fiberglass to resin ratio and a very small point that received a lot of pressure or force upon impact. Any proper nose repair should contain both fiberglass either cloth, milled or chopped and resin. You will need to sand the area well, and make sure it is dry. The board is technically not all epoxy. The surface will be either paint or a polyester gloss. Epoxy whether a 2:1 or UV will not properly bond to the paint or polyester.
To be completely honest, there is not a decent UV curing 'epoxy' on the market. None of them work well or bond properly to boards. A 2:1 epoxy similar to that used actual make the board is your best bet, but most people have trouble getting the mixing ratios correct.
This kit is compatible, and I have taken all the work out of getting the mixing ratios correct. There is also a brief write up on tips for a successful ding repair.
Brent, the typical "old school" nose guard is the best nose guard for an IS Sweet Spot. You can check them out at: