Extensions like RealURL, CoolURI and SimulateStatic have served us well for many years. They will likely continue to work in TYPO3 v9. However, they all share the same conceptual issues:
This is a companion discussion topic for the original entry at https://typo3.org/article/typo3-v9-roadmap/?type=0&cHash=355db65176030ee5ad24a13fbc870c9c