Custom "Page load error" page for Mir Kiosk

Hello,
we’re using the wpe-webkit-mir-kiosk snap on our kiosk machines. We have the server app running locally as a service. However, under certain circumstances (such as after a reboot), the server app will finish startup a few seconds after the kisok browser has loaded and tried to access the site. This results in the standard “Page load error” page being displayed. If the user taps “Try again”, the page will load, but this is still not great, as the kiosk appears to be broken.
We have a workaround for this - 10 seconds after the service is started, we restart the mir kiosk snap. However this is still suboptimal. For one thing, the users can still see the “Page load error” page for a number of seconds. Also I’m currently working with some legacy machines , which are slower than the ones we normally use, and on these machines even 10 seconds is sometimes not enough.

It occurred to me I could solve this problem if I could replace the “Page load error” page. Instead of the boilerplate page it would have my company’s logo, a spinner, and a bit of javascript that would try refreshing the page every few seconds.

Is this possible? If not, I would like to request this as a feature. How can I do that?

Thank you.

$ snap info wpe-webkit-mir-kiosk | grep contact
contact:   kontakt@glancr.de

Although, I have a feeling there may already be a issue for this. Have a look:

https://gitlab.com/glancr/wpe-webkit-snap/-/issues