Keep EPG History

Hi all
We use WebGrab+ to fetch EPG for a IPTV-System. We have some Channels we do timeshift. Thatfor it would be great if i can define somewhere how long WebGrab keeps the EPG-history by doing a incremental update, as example i need to keep the last 2 Days of EPG histrory. (we make 30 hours timeshift).
Does anyone know if there is already a funktion for that, or ist that a topic for the "idea-box"?
Thanks to the developer for this great tool!