China tourist visa for Australian visiting business friends in Seoul?

Hi there, I am in Australian Citizen who travels internationally approximately 6-9 months per year for work which often makes getting visa's in Australia difficult due to the short amount of time I spend in Australia. I am currently visiting business partners in Seoul until 22nd Feb, return to Australia briefly and then travel to Fiji, Vietnam, Laos, Cambodia and Japan until Tuesday 2nd April. I have a flight booked on an Air China flight, Sydney to Shanghai on Monday 8th Apri for my annual holiday leavel. I will not have enough time to apply and courier my passport to the respective Vietnamese, Cambodian and Chinese embassies during the short time I am in Australia.

I have a letter from my employer explaining my work situation and can provide itineraries for each of these trips. I am respectfully requesting to be issued a double entry Chinese Tourist Visa as I will be taking a tour of DPRK from 27th April to 2nd May (returning by train from Pyongyang to Beijing) and then departing on an Air China flight later that evening from Beijing to Sydney. I am happy to provide all accommodation bookings, bank statements, air tickets etc.

Could you please let me know if given my situation this would be at all possible to apply for the double entry Chinese Visa from either in Seoul or Busan? Thank you for your time and information.