FlyInside is custom tailored for FSX in many ways. If you are a halfway serious FSX simmer it’s almost certainly worth the money. No way that vorpX, which has to support literally hundreds of games, can provide the same level of integration with a single title that almost two years of work on supporting a single game can offer.
rFactor2 will indeed be fixed. Provided your issue was the startup crash that many (but surprisingly not everyone) encountered.