This is NOT the proper way to do an alignment...BUT it worked for me. On my 2017 Spark 2up, I had the engine just sitting in the hull (with wood shims holding the engine roughly aligned by eye and a tape measure), I attached the jet pump to the driveshaft and bolted the pump back to the hull (shimming the engine as needed to get the pump holes lined up with no resistance to screw the bolts in by hand), THEN I installed the aluminum shims under the engine mounts until she was rock steady. I was methodical and took my time but it worked out fine....absolutely no wiggles/wobbles/shimmys to date.....just finished the 2nd season.
Aluminum pop cans make for good thin shim material if you need to do some fine shimming.