No need to be too theoretical:
I see SPOT in many ETFs on US stocks, including indexing with Russell indices and “Goldman Sachs MarketBeta U.S. Equity ETF” (Solactive), “Vanguard ESG U.S. Stock ETF” (FTSE).
But also in “Avantis Responsible International Equity ETF”, “Invesco RAFI Strategic Developed ex-US ETF”, “SPDR Portfolio Developed World ex-US ETF”, funnily enough “Global X S&P Catholic Values Developed ex-U.S. ETF”.
And not in VTI, ITOT or ETFs on MSCI indices. Though for MSCI USA it could be just too small.