Depending how bad those lines are, high fill primer may or may not fill them. Another product is polyester primer which is really a sprayable form of filler. A word of caution - etch primer isn't always compatible with all overcoats and is really '60s technology. A better bet would have been to have used a good epoxy primer on your bare steel, i.e. DuPont, PPG, SPI then your 2K. The epoxy is not water permeable though the etch MAY be and for sure, the 2K will be.

Be careful with the poly primer especially if it's hot. It will set very fast and, from sad experience, will make a difficult to clean mess in your gun Use only about 1/3 of the catalyst at temps over 72-75*