It causes erratic problems, seems to interfere with exception handling. It's already disabled for Win64 MSCOFF.
@WalterBright created dlang/dmd pull request #12433 "fix Issue 21826 - MSCOFF output for Win32 should not use EBP for anyt…" fixing this issue: - fix Issue 21826 - MSCOFF output for Win32 should not use EBP for anything other than the frame pointer https://github.com/dlang/dmd/pull/12433
dlang/dmd pull request #12433 "fix Issue 21826 - MSCOFF output for Win32 should not use EBP for anyt…" was merged into master: - 8ab3d079ed08f8a934efae99981d087dcf25078d by Walter Bright: fix Issue 21826 - MSCOFF output for Win32 should not use EBP for anything other than the frame pointer https://github.com/dlang/dmd/pull/12433