both the Explorer and Enviro pHAT have an ADS1015 on-board, so the address will conflict on the I2C bus. That said, if you are going to do some selective wiring the workaround would be not to connect I2C on the Explorer.
… note that this workaround would only work with the Explorer pHAT, at least without also giving up the CapTouch found on the HAT version.
there are further complication i.e pin conflicts between the Explorer and the Display-O-Tron, and again you could choose not to wire up some of the Explorer pins, but at that point you will probably want to consider what function you want the Explorer to have in your setup and whether it makes sense to use it in such a reduced capacity.
Check http://pinout.xyz for more details about the pin conflicts between your chosen boards.