I absolutely agree with the idea of adding a filter as it is useful and fairly convenient to add on this website. I like the naming Classic/Modern filters.

The goal of speedrun always revolve around optimizing the run as much as possible which can be achieved in various ways. Having a "Modern" filter will not negate any run nor change the current leaderboard. It will mostly benefit curious speedrunners who want to follow up with and improve based on the most optimized runs without major skips (e.g. TA) and then slowly transition to modern skips when they feel comfortable. It can also serve as a way of comparison between similar runs (both old and new), add a sense of competition and be stepping stone for future runs with newer skips.