I would suggest an acrylic/water based primer. If doing so you don’t need to use knotting solution, it can react with water based finishes and, also, you don’t get the same degree of staining you would with an oil based finish.
However, if the knotting is severe I suggest you use knotting as planned, prime with an oil based primer and then one coat of oil based undercoat. Leave for 2-3 weeks for this to fully cure and then use the water based eggshell as planned. You may need extra coats to get the desired result though, in which case use a regular oil based eggshell or satin finish instead.