The Fed has already been buying ETFs, which is about a hair’s breadth away from buying stocks. I don’t doubt that they’ll buy stocks to prop up investors if the current stimulus proves ineffective.

Confirming story: https://www.marketwatch.com/story/the-fed-has-been-buying-et...

The possibly essential caveat being that the ETF's being purchased are (as far as publicly known) all bond ETF's.

Barely. They are only buying corporate bonds and the sum total of "Includes non-marketable U.S. Treasury securities, supranationals, corporate bonds, asset-backed securities, and commercial paper at face value" is 85.274 billion or a max of 1.2% of their asset sheet [0].

[0]: https://www.federalreserve.gov/releases/h41/current/h41.htm

There are some rumors this happened at the bottom of the '07/'08 crashes. A few traders swear something held the bottom.

I'm sure their canteen buys lettuce, and as it happens they've been getting quite adventurous with what else they're prepared to buy recently.

Well, lettuce has not been inflated by FED (yet), why would stocks have been?