I wrote a script to find "Tax Loss Partners" for niche ETFs. Am I missing any critical data points?

Hi guys, I've been manually harvesting losses for a few years (mostly the standard VTI -> ITOT pairs), but I recently got stuck trying to find safe pairs for some of my niche sector ETFs (like semis and biotech). I wrote a Python script for my own portfolio to scan the ETF universe and find mathematically "safe" partners to avoid Wash Sales. Currently, my logic filters for: 1. Correlation: > 0.95 (Price moves together) 2. Holdings Overlap: < 70% (Different enough for IRS Substantially Identical rule 3. Index Provider: Checks if they track different indices (e.g., CRSP vs Dow Jones). **Question for you guys:** For those of you who harvest losses on niche funds—would you trust these metrics alone? Or do you personally check other data points (like Sector Weighting or Top 10 Holdings) before pulling the trigger? Thanks!