hi,
I could not figure out how to set it on vyos. Looks like there is no config option.
From the frr docu:
bgp default-originate timer (0-65535)
Set the period to rerun the default-originate route-map scanner process. The default is 5 seconds. With a full routing table, it might be useful to increase this setting to avoid scanning the whole BGP table aggressively. Setting to 0 turns off the scanning at all.