Apply Pixie to Codex dataset

Hi, thanks a lot for the great work and congratulations!!

I wish to apply this wonderful method on my codex dataset to reduce manual work! However, I found that some cells are misclassified after the pixel and cell cluster annotation. I felt lost when I looked back and want to optimize the annotations. May I have some insights from you? Thanks a lot!
1. I got a slide of 28800x66240 pixels. Would you give some suggestions for selecting regions for annotation? Like, few ones with interesting structure? or scattered small fovs would be a better choice? Does size of fov matter greatly?
2. After I found that some cells are misclassified, what should I adjust to refine the resutls?
Like the image above shows the cells with label "endothelial cell". However, some of them do not express CD31 (the marker we select at all), and some of the cells with high CD31 expression are not labeled as endothelial cells. Would you please give me some suggestions under these circumstance?

Thank you very much and looking forward to you reply!!