I'm planning to glue down 3/4" 2.5" wide planks to plywood, a bit concerned about minimal glue layer thickness in case planks are crooked (and some will inevitably be). Decided to go with Single Step for that reason alone, to avoid taking additional measures to prevent plans sinking all the way to the substrate.

Do these spacers really work?

What other glues can be used for this installation? There is Bostik SuperGrip (which is surprisingly not discussed here at all), but the minimum amount I can buy (4 pails) is more than twice than I need.

I've used it alot but me thinks it's justa ploy to get LEED's credits.

Which of those two did you use?

So do the spacers work?

Related - there's also Bostik Ultra-Grip, the Lumber Liquidators branded Bostik, also has spacers. Looks to me like it's the same Single Step under a different brand name, with additional markup to top it off - is my hunch correct?

It's kinda interesting that there's no mention of Ultra-Grip on Bostik site (that I could find, at least).

Bostik makes the ultra-grip and others with branded names for different stores like HD, Lowes and LL. IMO the spaces do work. The best adhesive they makes is the Ultra Step-Single step and UltraStep-Single Step 2 which is white in color vs the other brown stuff. The white has a no limit while the brown has a 85% relative humidity (insitu) limit if remember correctly.