There is no set way to go about it. Adding images draws attention but it also makes you depend on the artist to release certain work.
In my case, I haven't released my novel waiting on my artist to finish a few drawings I have planned. It is worth the wait but.... it can get frustating at times.
Some novelist who can draw release a drawing with each chapter. I can't say I am fond of it since I prefer quality over quantity.
My suggestion to releasing images is not overdoing it. Your artist is already busy with your comic. Sure you can hire another artist but you should still not overdo it. Add images when you need a scene to shine. It can be to introduce a character or just a scene you really want to see drawn.
Another important detail is to have your image ready before your chapter is released so you may want to have a good buffer of chapters planned so your artist can finish the image without worrying that it will not be on time.
In a novel it is important to keep a momentum with your story. Otherwise readers might move on and forget all about you. Thus why you can't really delay a chapter. If art isn't ready it is better to upload the chapter and later edit it to add the image. It is still better to avoid this situation.
Find your own pace in which adding images works for you but do try to be consistant in your method so your readers can expect such chapters ahead of time.
Like any tool images can be powerful but it can be a big miss when misused.
In my case, I found a good rythm to let my artist finish the drawing with plenty of time to spare without me having to worry about having a mental breakdown just for missing an image.
For my romance novel i usually go with fluffy scenes and badass moments but no real action per se. In my action novel I just go with what looks the most badass. The fighting scenes I make are too complicated to show in 1 image so I let the reader imagine it for the most part.