Floor not level/toilet leans. I use 1x2's to make frame to put Dap inside to level out, then sit toilet on it. Is OK?

You do not want to use some thing permanent to set your toilet. You’ll regret it one day when there is a leak. Instrad.... Dry fit the toilet with wood shims and outline it all on the floor with pencil or something. Then use well mixed plaster of Paris in a gallon Ziploc bag like a pastry bag and apply a nice fat ribbon along your outline, on the line and inside it, leave a little gap in the back, set your toilet on top screw in and quickly clean up the edges so they are smooth and can be caulked, use a wet sponge. When the plaster is halfway set up, pull your wooden shims and fill the little holes they left. One day, when you need to remove the toilet the plaster of Paris will clean away with a screwdriver or a chisel. I learned this from a plumber who renovated old New England homes with odd floors and flanges. I’ve used this trick and it has worked for years now. I hope this can help somebody with their tipsy toilet.

DAP Flexible Floor Patch & Leveler is recommended for use up to a maximum thickness of 3/4". For applications up to 1/4" and let dry approximately 6 hours to a hard consistency. For thickness greater than 1/4", apply in multiple coats allowing each coat to dry completely between application. Given that this product dries to a flexible texture, it would not likely offer the stability (hardness) needed to provide the support for a large plumbing fixture.