Thanks for the follow-up, Marcus. Although the team was able to reproduce some laggy behavior with the PDF you shared, there’s unfortunately no immediate solution to speak of at the moment (besides temporarily using another viewer). It might be relevant to point out we haven’t received other reports of this particular behavior since your own.
As you might’ve read elsewhere in the forum, we’ve been working on complete rewrites of the extension and web app (see our roadmap) which will address this sort of issue and bring significant overall performance improvements. First betas are scheduled for after the summer and wider release before the end of the year.