This was my hope as well.
Finally set up local fulfillment myself. Continuing to use duckDNS. Had to switch to swag for nginx/certbot and HA on same docker host to finally get things working. Also using avachi on OpenWRT for mDNS repeating across VLANs.
I did stumble across this graph which allows you to see latency times for cloud vs local fulfillment. Look at the 95th Percentile Fulfillment Latency. Thus far, it seems to be <1 second on local vs up to 6 seconds with cloud!