Ok.. I've got one of these rx200's, had it for about 3 weeks now. I wanted it for the battery life and TC (Ti & SS). My other TC device is a istick 40W TC (Ti enabled from the secret button press) Now this was working grate with Ti dual coils about 0.17ohm 40W nice full vape and consistent until the battery dropped to 75% then it would get weaker and weaker to be expected, correct! So that was my base for the RX200.
Now with this RX200 from day 1 I've had Ti dual coil and SS dual coil's in a Brand new Bellus Tank. All I get is weak vape to burned hits. I've had the v3.0 FW and now just updated it to v3.10 FW yesterday. Still the same issue. the only way I've managed to get a decent TC vape is by customising the TCR value and even then e.g. Ti G1 is supposed to be TCR 366 and SS 316 is 92. In order for me to get a half decent weak vape out of Ti I have to set the TCR to about 450 then I can play around with the temp at about 430C to 480C any higher and I'm burning cotton. Same goes for SS my custom TCR is about 120 to 130 for a crap vape at the same temp range.
BTW all coils locked at room temp when frustrated room temp-ish! and the "new coil" option will only appear when the resistance is above the previous not below!
Now on to what I've just found out... I have read on a reddddit forum and at least 10 people on there confirmed it, is that when getting a weak vape in TC is to load the very first FW onto the RX200 then load the latest v3.x FW. They are reporting it fixes the weak and early temp protection.
I'm at work and I put Kanthal it last night (0.4 ohm dual coil and it's chucking at 50W like never before!!) So I can't test right now, Can anyone out there test is and report back other wise I'll do it later when I'm home.