As in the title it is true that you don't have to copy paste the gallery shrotcode after it is generated as other plugins does.
You can initially keep shortcode as
[flexi-gallery attach="true"] in any number of pages & post and images/post can be added slowly by going into the respective page.
Initially this shortcode will have a form with one title and one file upload field with submit button as on the picture below.
For example: You wanted to add category to the form so that it will Title,category,file selection & submit button. All you have to do is use [flexi-form] shortcode with it's attribute but don't forget to add
attach="true" into the shortcode.
[flexi-form attach="true"] [flexi-form-tag type="post_title" title="Title" required="true"] [flexi-form-tag type="category" title="Select category" ] [flexi-form-tag type="file" title="Select file" required="true"] [flexi-form-tag type="submit" name="submit" value="Submit Now"] [/flexi-form]