Any interaction with anyone in K4 is part of the interview process, you can get called a day after you submit the application with an internal Rec letter or you can get called with no internal recommendations too. When K4 calls they screen and if they like what they hear, they tell you interview dates, the follow up email with hotel and what to bring for interview etc is very slow coming. The HR department is small and working flat out as the hiring is aggressive at the moment. I know I am saying " be patient" and yet follow up at the same time to confirm your interview date in YIP, but thats what needs to be done. also check you spam folders if you've received an offer to interview.
As for updating a 3 year old application, maybe re-apply with a different email or you could PM me some details and I could make an inquiry on your behalf on how to update an application.
and lastly working 12-15 days a month is not the same as 17 consecutive days away. the commute plus 16 days 'ON' Flying around the world at the moment consists of sitting in an airplane then getting escorted to HOTEL Lockdown. FULL STOP. The glamour and experience is not what it was pre-COVID. Hopefully it will change in the future but I doubt that is the case in the near term future.