When exporting more than 10,000 visits, it is recommended to set the offset as mentioned in https://matomo.org/faq/how-to/faq_24536/#important-note-about-high-traffic-piwik-servers , however this can only be achieved by adding the parameter in the URL manually or by writing the logic.
A feature to add the offset value from the UI would be helpful, may need to provide some guidance around this feature on how to use it