Turkish delight is way too soft and too sweet. How can I make it more firm with way less sugar?

I'm following this recipe for Turkish delight.

There are a few unwanted outcomes. First, is the instructions for preparing the cornstarch results in unwanted lumps, even when using an electric hand mixer. So, next time, I'll probably pour all the water right away, and dissolve before heating it up to thicken it.

Secondly, after sitting on the counter overnight, it's a bit too soft, in my opinion. I want it to be as firm as the cotlets that I could buy. When cut into the small cubes, they do hold their shape, which is good. And also, the cornstarch/confectionery sugar mix doesn't get absorbed, which is also good, but it's just too soft. Could it just be a matter of time that it will actually become firmer by just being stored in a box or sitting open on the counter?

But my biggest issue is that it is just way too sweet, seemingly much sweeter than putting 1 tbsp of plain sugar in my mouth. I think I want to use just 1 cup of sugar because the 4 cups just seems too much. But I'm afraid that just 1 cup of sugar dissolved in the 1 1/2 cups of water won't reach the 240F required to reach the required softball state. Can I just use 3/8 cup of water for that 1 cup of sugar? But then my candy thermometer won't be able to read it because the solution would be too shallow. (I don't have a smaller pan).

So again, primarily, how can I use way less sugar than the recipe states to significantly reduce the sweetness, and achieve the same firmness of cotlets?