Your points are well taken. I recognize the difference of interest payments and taxes/SALT. My issue is the IRS interpretation/guidance opens the door to the full $10K. The language on the IRS site interprets the law/code.
I believe the law is muddled (well, congress wrote it) and not articulated to reflect a variety of situations why file MFS. In my case, my wife is on a US work visa (G4) that excludes her from US income taxation. If we file jointly - it triggers a whole wave of potential IRS claims to her foreign assets/income generation (potential or real).
