PfSense for DHCP Server

Hi All,
I was wondering if someone could give me some insight into something. There are events that i do (well did more often before the pandemic). I actually use Ubiquiti edge routers for most of the routing. But i wanted to move in a directions to at least spread the load on the routers. I was interesting possibily getting an old server from ebay and install PFSense on it specifically for DHCP. I would like to know what the recommendations would be if i wanted to get anywhere from 5k to 30k clients online. Im not worried as much as the routers being able to route. But with events the crowd usually swarms in, in large dumps and i want a dhcp server that can handle ALOT of DHCP Request at a time.
Thank you !!

You could find a sever on eBay that is similar in specs to their higher end devices

@joshhboss Ubiquiti switches support a maximum number of DHCP leases (Total): 2048
If pfsense supports the same number, then you should consider getting multiple light servers instead of a big one in order to get the 30K total number.