Assuming there is some culling, I’ve found myself somewhat obsessed about the methods of dataset-culling. If there’s a single outlier, for example, some methods would skip it, where it should really be highlighted.

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000... is a good algorithm to use to keep peaks. At a maximum you need 4x the chart width data points. In practice, you can easily reduce that. I've implemented the algorithm before and it can be done in linear time.