Looks like a reasonable argument. But truth to be said, i didn't think that up myself.
This redundant regex testing can be seen in the existing pollers:

https://github.com/fzaninotto/uptime/blob/9d159ab7cf3db58787a309270cf4be91a4d3fa54/lib/pollers/udp/udpPoller.js

```
UdpPoller.validateTarget = function(target) {
  var reg = new RegExp('udp:\/\/(.*):(\\d{1,5})');
  return reg.test(target);
};

UdpPoller.prototype.initialize = function() {
  this.udpServer = getUdpServer();
  var reg = new RegExp('udp:\/\/(.*):(\\d{1,5})');
  if(!reg.test(this.target)) {
   console.log(this.target + ' does not seems to be valid udp url');
  }
```