I move my freighters and lone JF with in-corp alts all the time.

I just..... don't get decced. All you need to do is not be noticed, it's not hard.

Don't undock 4 freighters at once with the same corp ticker, if high values need to be freightered, use a DST bricked like a goddamn tank to exit 4-4 with a Basi or two already outside to fleet warp it out to an insta (fuck you grid load times, I got you) and rep it if it gets bumped by mistake or intent, then meet up with the freighters a few jumps out

Avoiding decs isnt hard if you don't wave ISK flags around all the time. My alt corp has never been decced in it's 8 years of existence, I average about 45b in sales a month from 4-4 alone, and I export considerable quantities of capital parts as well.