Hello everyone i made this topic to prevent others being ripped off like us by this company.
We perfect our efoil product for nearly 3 years now and we worked a lot with maytech (sometimes we had no choice).
Short story when we first bought the "Waterproof " Remote V1 we tested it in the sea and after one hour the remote was trigerring full throttle by itself (a bit dangerous don’t you think), we can proove it with a video we made that day. 
Maytech asked us to send back (we paid the shipping back) and we had to pay again 60USD to get the new version, they refused free replacement. We agreed to pay and got the crap V2 (with the screen that fill with water)
In july we bought a Remote V2 + “200A” Vesc, once we tested it we found out at 70AMP (motor phase) the motor started cogging really strong and broke propellers or pins (lost sync ?).
The motor is perfectly functionnal on other vesc. And we tested everything possible (BLDC, changing all settings) the only way to make it work was limiting current to 65Amps… We use VESCS for 2 years now and our setups usually work on cheap VESC 6 as it is really efficient and never had such strange issue.
We explained to Maytech and sent VESC XML settings, Videos, at last we wasted hours talking with them, they said ok send back we will repair, of course we refused to pay again for shipping. And now we are back from holidays they dont want to hear nothing from us, they only offer 90USD coupon 
To conclude, never buy to that company, pray that a new remote will be developped by another company otherwise they will take your money and wont ever help you if their crappy product brake