Replacing 3DR 20A ESC with mini quad ESC

I’m rebuilding a 3DR X8 and considering swapping out the eight ESCs that weigh 21g each with the tiny miniquad ESCs that weigh 4g each. Both are rated at 20A with a burst to 30A. This would save me 136g! (Not including the additional ubec I will need since these are opto.
An example of the ESCs I’m considering are the LittleBees hobbyking.com/hobbyking/stor … BEC.html

Does anyone see a problem with using a BLHeli miniquad ESC on a big X8? I know it isn’t designed for a platform like this, but does it matter?

Thanks for your opinions.