on slave system env I have FOO set. This is also the name for a build parameter. I expect FOO to be set during build to parameter value I pass to build, but with envinject installed (even when not enabled on my job) build parameter is overiden with node environment.

This wasn't the case in 1.76 and previous, seems this has been introduced by https://github.com/jenkinsci/envinject-plugin/commit/ed245ce8c7b4562159291a3599d6638e65301155. Anyway I don't understand JENKINS-14437 use-case, I doesn't make sense to me to override build parameters (why would you define a parameter then ?).