I guess things have changed on here- I remember a few years ago someone bragged about working for free at an aerial survey company to build twin time, and everyone thought that was a good idea.
I have to admit I don't see this a shortcut either. It could even be good experience, like
@JDean3204 said about IFR ropes. I was thinking that since so many people on here feel this is an inappropriate shortcut and that instructing is the way, the truth and the life, interviewers at future jobs potentially could. But I reckon Kingairer is right:
With how bad the pay is I suppose you could argue going to Southern puts downward pressure on pilot compensation or "brings down the profession" but from what others have said it's only a little worse than other 135 2-pilot operators, plus if people are arguing it's useless time I don't think there's a good case for that. I suppose another issue whether you'd have the time and funds to get your multi-engine rating while at Southern.
Aerial survey still seems like it could be a great option for you. I don't know if any survey companies are hiring right now, and hiring tends to be very seasonal. But with more and more regionals hiring again there's hope the survey companies might begin hiring this year as well.
Admittedly I wasn't on here back then, but I thought the idea behind "don't chase upgrades" was that upgrade times are hard to predict, so if you start all over again at the bottom of another seniority list hoping for a quick upgrade, it could easily change and you won't upgrade any sooner anyway? It definitely seems to vary though. I remember in the mid 2010s people said PSA was a scab airline and you shouldn't go there even though the upgrade times were short, but there was also a thread where people berated
@Screaming_Emu for
not going there for a street captain slot.