When the resin has reached the exit port and everything appears to have wet through, close the exit but leave the inlet side open for a couple of minutes. This should allow enough time for the resin to completely fill the part

On such a small sample, you can likely get away with using no spiral and a narrow strip of flow mesh at the inlet side should be enough. On larger pieces, it's common to cut any flow mesh just before the exit line (about an inch or so) and this helps to slow things down and allow time for the resin to flow to all areas before starting to flow up the exit line. Another narrow strip under your exit port will help to evacuate any air in the resin as it reaches the end of the part. So, a narrow strip at the resin feed side, with another strip at the exit should leave enough of a space inbetween to allow for a slow and thorough wetting-out of your part and, hopefully, no dry spots when cured