Have you tried aircraft scatter? VK1 has a daily VHF Dx Net where contacts extend out to ~400 to 450 km via AS. VK1 and our 48 summits are under multiple 35,000 to 40,000 ft flight paths of Sydney - Melbourne commercial aircraft, one of the busiest aircraft corridors in the world.
Peak 2m SSB DX activity occurs between 07:15 and 09:30 local time.
A common source of location errors is the “wrong locator on QRZ” problem. It is conspicuous in the case of VK because QRZ defaults to the centre of a country as the default locator. This gives distance errors of up to 3000 km for many VK operators. The centre grid square for VK is somewhere a bit west of Alice Springs.
Thats why the rules of the challenge say don’t get locators off QRZ, and if logging with POLO that means turn the automated QRZ lookup off.
We have one log in vk1 claiming a 2900 odd km contact with a vk1’s second callsign, a minute after contacting the vk1 callsign. Despite being requested to correct the error, he has done nothing to fix it.
The rules don’t specify what to do with operators with multiple callsigns. However as it’s just a table on a website, no sheep station prizes, doing what others do seems to be the practice. It fills the logs.
73 Andrew VK1DA/VK2DA
That’s what I did last night - around the same time you wrote this post - possibly the increase in my score was what inspired your post 
The increase in my score inspired me to do some housekeeping, as it was a bigger increase than I was anticipating. Sure enough, there were two stations worked on 2m SSB at the weekend that didn’t know their Maidenhead locator, so I took their postcode over the air for later conversion. Then forgot to convert!
So I had two recent contacts in the log with “locators” OL26… and BB73…! Several thousands of km distance points soon vanished when I corrected the logs! It was Oldham, not China. It was Clitheroe, not Antarctica!
Now they would have been impressive DX on 2m 
That is NOT an excuse to allow inaccuracies or errors!
Are satellite contacts permitted in the challenge?
I received a VHF/UHF linear satellite the other day but don’t worry I couldn’t figure out the doppler tracking and inverting/non inverting.
Yes