Hello! I have discovered some interesting connections regarding the prestige system. Maybe it was stated somewhere else, but for me it was new. So I wondered, why my small mine train coaster with 9.89 excitement rating got such a bad prestige value (not even 200 and it was new, peeps hated it). So I started a litte investigation with the mine train. Soon I discovered that the coaster length has a huge impact on the prestige value:
I built 5 different mine train coasters without scenery. Each with a pretty bad excitement rating of 4.61 and different length (100m, 250m, 500m, 1000m, 2000m). You can see the big impact of the coaster length on prestige. Ok, the rise of the curve becomes flatter at the end, but this effect will be only strong on coasters over 1000m length.
Because I could not believe this, I built a 5000m coaster with a poor excitement rating of around 2.27. Prestige value: 788! So you could guess that excitement rating has no effect at all on the prestige value?
Not true: I built a bunch of coasters to check this. Now with constant length of 250m and later with 500m. Just the excitement rating is increased (using better drops, increased chain speed and so on). Here are the results:
As you can see, excitement rating affects prestige, at least with coaster lenght of 250m and 500m. But the effect will also be decresed on excitement ratings over 5 or 6. And if you want to tweak your coaster to come from 8 to 10 or something: Forget it. Excitement ratings over 8 seem to have no influence at all on the prestige value. The blue curve is also a little bit strange, because it has some kinks in it. I don't know how Frontier calculates the values.
Not shown in the picture but also interesting: Dependant on the coaster length the excitement rating has a different percentage influence. For example: If you increase the excitement by 131% (from 2,27 to 5,25) on the 5000m-Coaster you will get a prestige rise of 1,4% (788 to 799). If you increase excitement by 118% (2,30 to 5,03) on the 250m-Coaster, prestige is rising 104% (121 to 248). Maybe this is because the 5000m-Coaster is alredy near the prestige top value. But also a small 100m-Coaster has a worse convertion ratio from excitement to prestige compared to the 250m-Coaster. I don't know why this has to be. So, you totally should avoid short coasters.
Last note: You can enable the full scenary prestige bonus with 2000 mini objects (just use the 0,50 cent stones or geometric forms). More expansive object will do the same job and will have more impact on their own, but if you look on the percentages you should use the extra small ones. I recommend to build a blueprint with 2000 interleaved mini-stones. Then you can place it at every attraction for 1000 Dollar and get the full bonus. It does not matter where you place it. For the mine train coaster you will get +150 prestige. For the sleigh tracked ride you will get +540 prestige! So this is different for each category.

I built 5 different mine train coasters without scenery. Each with a pretty bad excitement rating of 4.61 and different length (100m, 250m, 500m, 1000m, 2000m). You can see the big impact of the coaster length on prestige. Ok, the rise of the curve becomes flatter at the end, but this effect will be only strong on coasters over 1000m length.
Because I could not believe this, I built a 5000m coaster with a poor excitement rating of around 2.27. Prestige value: 788! So you could guess that excitement rating has no effect at all on the prestige value?
Not true: I built a bunch of coasters to check this. Now with constant length of 250m and later with 500m. Just the excitement rating is increased (using better drops, increased chain speed and so on). Here are the results:

As you can see, excitement rating affects prestige, at least with coaster lenght of 250m and 500m. But the effect will also be decresed on excitement ratings over 5 or 6. And if you want to tweak your coaster to come from 8 to 10 or something: Forget it. Excitement ratings over 8 seem to have no influence at all on the prestige value. The blue curve is also a little bit strange, because it has some kinks in it. I don't know how Frontier calculates the values.
Not shown in the picture but also interesting: Dependant on the coaster length the excitement rating has a different percentage influence. For example: If you increase the excitement by 131% (from 2,27 to 5,25) on the 5000m-Coaster you will get a prestige rise of 1,4% (788 to 799). If you increase excitement by 118% (2,30 to 5,03) on the 250m-Coaster, prestige is rising 104% (121 to 248). Maybe this is because the 5000m-Coaster is alredy near the prestige top value. But also a small 100m-Coaster has a worse convertion ratio from excitement to prestige compared to the 250m-Coaster. I don't know why this has to be. So, you totally should avoid short coasters.
Last note: You can enable the full scenary prestige bonus with 2000 mini objects (just use the 0,50 cent stones or geometric forms). More expansive object will do the same job and will have more impact on their own, but if you look on the percentages you should use the extra small ones. I recommend to build a blueprint with 2000 interleaved mini-stones. Then you can place it at every attraction for 1000 Dollar and get the full bonus. It does not matter where you place it. For the mine train coaster you will get +150 prestige. For the sleigh tracked ride you will get +540 prestige! So this is different for each category.