I do think adding some translucence to the cum has made it look better, but agree that it's not as good as it could be. Rastifan creates some pretty awesome cumshot images, I wonder if you could learn anything/get some advice from him?
Regarding extending the cumshot scenes. I do really like the idea of a woman slowly cleaning my cum off her body with her fingers and licking her fingers clean - that is unquestionably hot. I think that as well as having some clean-up images/scenes, the actual cumshot scene (cum flying through the air and splattering on/in the woman) would really add to the climax. For example, I think you have either three or four splatters of cum on the model after the cumshot in chapter 2, and she cleans each one off in successive pannels. I would like to see the images where each splatter lands on the women (i.e. first glop of cum comes out, and splashes on woman, second glop comes out... and so on). In my opinion, the moment of the character's orgasm instigates the erotic climax (mental and/or physical) for the person reading the work too, and so it's a good idea to extend that moment to maximize your reader's arousal/climax.
If you are starting to think I'm suggesting too much be added, I would say sacrifice some of the clean-up images for the cumshot images: It's not every girl who will lick a mans' cum off her own body, but every orgasm does include spurting cum

Best regards and thanks.