You asked. Here's everything i know.
He's incredibly talented, great voice, great songwriter. I went to see him in June in Dublin with my sons (big fans). Fab night. Massive band. Varied age in crowd. Loads of girls wearing tiny shorts and cowboy boots.
Best songs are Something in the orange, nine ball, pink skies, revival, oklahoma smokeshow... there are more but I can't think right now.
Zach himself is a bit 'problematic' but I think it's most drink related. He has recently stopped drinking and released a song (or a snippet of one, not sure) criticising ICE, so he got a bit of republican backlash (dodgy ground for country singers but just fine by me). He is known for tweeting things and deleting in the morning. He got famous quite quickly whilst in the army (or marines) after posting videos on YouTube. He's still pretty young and not very media savvy, might have a bit of pstd or something.
His problems before largely centre around his ex girlfriend (Brianna 'chickenfry' LaPaglia) who is a youtuber (or similar) and a bit of an attention seeker. I did a bit of a deep dive about 6 months ago on what he's supposed to have done (can't remember it all) but I think it's largely he broke it off, she posted loads of videos about the break-up and then claimed he was abusive and he tried to pay her $12million to stop her talking or something. I don't think she has said he was physically abusive, more controlling (said he was embarrassed because she wore a see-through dress to some red carpet event). He also got into a row recently with some other country singer at a festival and tried to fight him. Dunno if this was before or after giving up drinking.
I don't think he's an angel but I don't believe he's a bad guy either. Just made some silly decisions. Yes, I bought more tickets to see him again.