TortoiseGit SSH-Client Setting Change Reconfigures Key-Format and Agent-Usage Without Unified Migration Path

TortoiseGit's Settings > Network > SSH client provides a binary selection between PuTTY (TortoiseGitPLink) and Git for Windows OpenSSH, yet the underlying Git transport configuration resides outside the UI. The chosen backend determines whether Pageant or ssh-agent is used, whether private keys are interpreted as .ppk or OpenSSH format, and how host-key acceptance prompts are presented. Switching the setting does not automatically reconfigure existing credentials or migrate key formats, and the interaction with Git for Windows's own ssh.exe invocation, the GIT_SSH environment variable, and repository-specific .git/config entries remains ambiguous in mixed-deployment environments. Exact defaults and minimum supported versions vary by release, as documented in TortoiseGit and Git for Windows release notes.

Does changing the TortoiseGit SSH-client setting alter active repository authentication when .ppk and OpenSSH keys coexist? What criteria does TortoiseGit apply to select between Pageant, ssh-agent, and direct key-file loading after a setting change? Under what conditions does host-key acceptance behavior differ between the two backends in non-interactive or scripted contexts?