[Q] samsung galaxy s4 metropcs 4.4.4 help topic

Please if this thread breaks any of the posting rules at least give me an answer before its deleted, or send an email. I’m pretty sure that I’m not the only one in this position.
I have a Metropcs galaxy s4 baseband version M919NUVUFNI3 on version 4.4.4
I’ve been reading for weeks on my spare time and I typically never like posting anything in any forums but this should make it obvious I’m looking for an answer here. I just want to be able to throw some ROMs on my phone to mess around with like I use to on my galaxy s3, but I’m at 4.4.4 and everywhere I go seems to contain people going on and on about us being screwed by Knox and Samsung if I try anything.

So here’s the cold cut question: ------------------------------------------------------------------------------------------------------------------------------------------
Can I root my Metropcs galaxy s4 (m919n) that’s currently on 4.4.4 or do any method to get a custom rom on it without Knox or Samsung knowing about it?
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I don’t care about my warranty but I don’t want to get blocked by my carrier or get any sort of warning.
ANY help is appreciated.
-Julian