https://www.ptc.com/en/support/article/cs130904?language=en&posno=1&q=Integrity%2011.2%20and%20Implementer%2012.5&source=search
and here is says "
- IMPLEMENTER SUPPORTED INTEGRATIONS WITH PTC WINDCHILL RV&S (FORMERLY INTEGRITY LIFECYCLE MANAGER)
- 12.0 - Integrity 10.0-10.9, 11.0-11.2, 12.0-12.2, Windchill RV&S 12.3-12.5
- 12.1 - Integrity 10.0-10.9, 11.0-11.2, 12.0-12.2, Windchill RV&S 12.3-12.5
- 12.2 - Integrity 10.0-10.9, 11.0-11.2, 12.0-12.2, Windchill RV&S 12.3-12.5
- 12.3 - Integrity 10.0-10.9, 11.0-11.2, 12.0-12.2, Windchill RV&S 12.3-12.5
- 12.4 - Integrity 10.0-10.9, 11.0-11.2, 12.0-12.2, Windchill RV&S 12.3-12.5
- 12.5 - Integrity 10.0-10.9, 11.0-11.2, 12.0-12.2, Windchill RV&S 12.3-12.5
"
so yes Implementer 12.5 is compatible with Integrity 11.2