I dunno. These don't seem to me like leading indicators. More like coincident or lagging indicators for a recession. If you wait till yoy industrial production and retail sales growth are negative, I'd say you're already well into a recession

Have you read the GTT paper?
Growth and Trend: A Simple, Powerful Technique for Timing the Stock Market
philosophicaleconomics.com: Growth and Trend: A Simple, Powerful Technique for Timing the Stock Market

"Empirically, for the U.S. economy, the strongest historical recession indicator is Real Retail Sales Growth. Since the Census Bureau began to collect and publish it as a series in the late 1940s, it has expeditiously nailed every recession that has occurred, giving only a few false positives. Notice how the blue line consistently crosses below zero at the left sides of the gray columns, the beginnings of the recessions.

Real Retail Sales Growth is a truly fantastic indictor, a direct line into the health of the U.S. consumer, the engine of the U.S. economy."

"Another accurate recession indicator is Industrial Production Growth. With the exception of a single costly omission in the 1974 recession, it’s done a very good job of accurately calling out recessions as they’ve happened."

Stock market indexes are considered among the best leading indicators for a recession.

The indexes are too hair-trigger. They take you out too many times when there is NOT a recession.

People should note that timing is not for increasing your return; timing is for avoiding the worst of bear markets.
The problem is that timing keeps you out of the market in the early stages of the bull market -- which is where the quickest upswing is.

Which leads to an counterintuitive & surprising conundrum . When you are young and far from retirement and still growing your portfolio you are better off overall by NOT doing timing. It is when you are in or near retirement that timing is most valuable, because you don't have the time to wait for the market to recover.