An American Pale Lager, eh? That’s exactly what this is. Do a diacetyl rest for 3 days in the 60s Fahrenheit when gravity hits 1.026, then bring back down to 50s until fermentation subsides completely, then wait a few more days just to be sure it’s fully attenuated, and then crash to lager. Lager it for as little or as long as you like.
I’ve never used the Steam yeast before, much less in the low 50s, so I’m not sure if that will work well for you or not. Nice experiment though.
If it’s actively fermenting now, you could bring it up into the 60s at any time, then leave it there until it reaches FG, plus a couple days after for the d-rest. Then dry hop, crash, and lager.
+1. And sometimes on a hoppy lager I’ll lager it until I’m happy with the clarity, warm up to the mid 60s and dry hop for 2-3 days for some fresh dry hop character, then cool to serving temps.