yeah, i wish there was easier ways, i now keep a backup in the form of my own relay, which i periodically, and currently manually, pull down relevant events from other relays and push to my test relay, which i then export to jsonl - currently my whole file is 20mb and compresses as tar.xz to 2.9mb (a lotta repeats of my and other pubkeys)
i can push that whole backup back onto my relay also, i haven't gone much further in this direction because it's a little orthogonal to my task of building a relay