INA229-Q1: Are pins INA239-Q1 and INA229-Q1 compatible? Software compatible?

Hello,

The INA229-Q1 and INA239-Q1 are pin compatible, however they are not software compatible because some the registers have different sizes and the conversions and configuration values are different as well. 

Fortunately, we have both of these devices available in SysConfig, which is a code generator that can be used to help you make the software transition:

https://dev.ti.com/sysconfig/index.html?product=ascstudio