Wood glue with diluted water can enhance a wood putty formula in many ways. It can increase adhesion, tensile strength, and flexibility. The formula won’t shrink and is less likely to crack. Another benefit is that the compound is paintable/stainable.
Simply add wood glue to the mixing water and stir thoroughly. The ratio can vary, but you can easily judge your mix by the color and consistency of the water.
After the glue-water is stirred, add the powdered putty and mix well.
The oak saddle which divides the wood floor from the ceramic tile is sitting on an un-level surface. The saddle had to be raised an inch and a half on the left side in order to be flush with the tile. After some wood shims and finishing nails were installed, the wood putty/wood glue mix was used to fill the entire gap between the oak divider and the floor. (Tape was used to mask it off.)
The saddle and the wood putty were both stained with the same color: Golden Oak.
When the heavy-set new tenants moved in, they initially gave the whole apartment the stomp test. So far the repair has held up.