Thanks for the details. Maybe we can try to solve some of the bigger items first and then circle back on the smaller ones.
You can use two features to accomplish a fully filled iframe. The first is to make sure you are using kiosk mode for your display URL. Kiosk mode will hide the top navigation bar, the ... menu, and other features that are only needed during editing. You can do this by appending ?kiosk=true to the URL:
The second would be to use scrolling="no" in your iframe definition. This would look something like:
<iframe
src="https://sharptools.io/dashboard/view/XXXXX?kiosk=true"
scrolling="no">
</iframe>
SharpTools should only add Spacer tiles if there is space left between two real tiles when you save. If you put one tile below another one and there is empty space remaining to the right on the first row, then spacer tiles will be added (since dashboard tiles flow left-to-right). If this isn’t what you are experiencing, a video might help us troubleshoot.
The only time I’ve seen the ... off the screen is when tiles that were larger than the screen-width were used, causing the canvas to extend beyond the width of the screen. Again, a video might help me better understand what you’re seeing here.
I would also note that you can edit your dashboard from another device or browser window and when you save changes, they will be pushed instantly to other devices/browsers that are viewing the dashboard.
The following example is a bit contrived just show how things work, but I’m using an iframe which fits 2 tiles wide by 2 high with the default tile sizing. Then in another browser window which is much wider, I’m laying out the tiles left-to-right and then saving to watch them get reflowed in the iframe.
(Alternatively, I could have adjusted my ‘editing’ window to approximate the size of the smaller iframe [or exactly match it using Chrome Developer Tools as noted above], but the intention was to demonstrate how the left-to-right reflow of tiles works)