New Max 4 that I ordered from amazon as a spare got here today. Soldered up some qs8's and it's working great. I will say though that after using the max 5 g2 and the max 4 back to back I'm a little salty with the missing settings on the max 4. iirc I thought the max 4 came out when the max 8 g2 did but they left all the extra settings that all the G2 esc's have off the max 4. No timing adjustment but max8 g2 and max 5 g2 can both do it.
Very weird of them to leave the max 4 with the basic settings of the max 6 and max 5 g1
I also saw a noticeable difference in the power between the max 4 and the max 5 g2 when using 12s and my tp 5870 750kv. The max 4 definitely made the rig feel like it had more power.
I just got a HW Max4 and the 70125 motor about a month ago I put in my 5iveT, I'm running 12S also and so far it's been good. Just like you I was bummed with the lackluster amount of settings we get. I have the OTA programmer also, found a guy on fakebook that said he had the turbo boost feature available with his. He had both the OTA and the program box and it only showed up with the program box. He even took a video to show me that was the case, well I ordered the program box also trying to get some added features but no luck for me. The box had the exact same options list the OTA had. I think HW may have took some stuff away which sucks, maybe they think extra features were causing more warranty issues who knows.