prasath not to my knowledge, no. The API (basically the /search endpoint) will be the way to go to extract user fields. Using a LIMIT 1000 is definitely recommended as you will run into issues when bombarding the API trying to exceed that 1000 limit, a) requests are gonna take very long with that already and b) they'll just time out either from khoros side or from your http client that you are using to send the requests. You can run them concurrently (e.g. parallel), but then I'd highly recommend you implement some logic to deal with quota exceeded errors you'll eventually get back from the API if you overdo it, which you should then retry.
The only faster way I'm aware of is a direct SQL database dump that you can get from Khoros, but that comes at a pretty steep price (10k $ +) per single export and then you'll have the pleasure of deciphering the Khoros DB-structure to find all the relationships etc. that you might need in the haystack of tables you'll get from that dump. Therefore I'd recommend going the API route...