Hi Alain,
sorry, don't know the Tarot frame.
I don't want to convince you of using a quad instead of a hexa, but I think it will be not that easy to stay in the 2.5kg limit.
Maybe you should opt for an okto config, somehow like Menno has shown here:
viewtopic.php?f=38&t=3952#p27903.
O.K., he is using parts which are not available yet, but if you use ESC32 with CAN and the M4 (instead of AQ6) it should be possible to stay below the limit. Sorry, don't know which motors he is using, but he gives some info on the components weight: i.e. the 16mm 1.5mm wall carbon tube is 38g (without mounts etc!).
I will also fly my new quad with QUATOS. I things work as expected the AUW weight of that craft will be very close to 2kg incl. a 6000mAh 4S flight pack --> lets say 400 to 450g for GoPro + Mount + x.
If I want to carry larger loads (bigger camera) it would be possible to fly with a PID firmware since I have plenty of resources left (max payload is somewhere between 1.5 - 2kg for the setup).
Using small motors will not allow for this - even on a Hexa - without reducing battery capacity (reducing flight time).