Hi @Zamzam, welcome to the forum 
If you only swap out the thrusters then there aren’t really any additional risks to the power system. The main things to be aware of are:
- Excessive power draw leading to the onboard computer restarting due to undervoltage
- This post is from a while ago, but covers a few relevant mitigation strategy options
- Extended operation at high thrust levels overheating the ESCs and/or overwhelming the power sense module
- It is safer to limit high thrust to brief time periods, and not all thrusters at the same time, to allow things to cool down in between
- Note also the continuous current limits of the battery
- An aluminium enclosure can help transfer heat away from the components and into the surrounding water
- It is safer to limit high thrust to brief time periods, and not all thrusters at the same time, to allow things to cool down in between