It is possible to connect multiple KPIs to each touchpoint as you need and there is no limit to the amount of KPIs you have defined. However, it is not recommended to have so many KPIs that it is impossible to track them all. They should be KEY performance indicators for your business.
Talking about Customer Experience Journey Mapping and beyond
How many KPIs can I create?
It is possible to connect multiple KPIs to each touchpoint as you need and there is no limit to the amount of KPIs you have defined. However, it is not recommended to have so many KPIs that it is impossible to track them all. They should be KEY performance indicators for your business.