Finish / rewrite Wordpress plugin functionalities

Rewrite / expand a Wordpress Product design plugin with a new functionality. it concerns the page [login to view URL] and the options to be made can be found on: https://www.ulftsign.nl. As you can see, the current site is being replaced by the new wordpress site, all the functionalities of the old site must be reflected in the new one that is already more than 90% complete. Due to a lack of time I would like someone to adjust the existing Product design plugin to the "still" missed functionalities. Ao. Length x width adjustments must not influence the example. This can be solved in 2 ways 1) the preview must not contain any empty spaces (use image crob), ie adapt the text to a fixed canvas 2) a static canvas just like on the old site and only adjust the Length x width dimensions. The font large option must be removed. The option mirror letters must come in, you can do this using the [login to view URL] the choice must come back on the invoice and in the mail from to the site owner. The price calculation must be adjusted / set, the exact calculation will follow. If I have forgotten something then it will be something small .. but this was it for the big lines.