Incidentally, There's no iPad version - so not that kind of tablet.

I think the white band is the screen. You asked about it on your other current thread and I suggested a solution for it there - the commands contained in this blog by Remy Monsen should help.

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Making and positioning a grid.

In these example images I have turned the usually invisible white screen object grey to show the extent of the map, and also to illustrate what happens when you use the collar commands.

Make your grid deliberately too large by using the Select points option above the Apply button and place it very approximately in the right place. At this stage you are merely using the map to judge how many hexes you want - a bit like stretching a length of curtain material over a window to see if it will fit. There is no need to worry about accurate placement. Be more concerned that you have enough hexes.

The new grid will have generated its own snap grid, which is useless from our point of view. Next we need to make our own new snap grid and move the drawn grid to match it.

To create a new snap grid right click the Grid button and select New.

Pick 2D Hexagonal and Continue...

Give your new Grid an appropriate name and adjust the settings to your taste, then OK

Your new snap grid should appear in the drawing window.

To move your drawn grid into alignment with the new snap grid, turn off Snap and turn on Attach. Then use the Move tool and pick up the grid at the corner of one of the hexes. Don't click the outline of the grid, but the side of one of the hexes.

While you have the grid hovering on your cursor mid-move operation, turn Attach off and Snap back on. You should be able to snap the corner of your hex to the right position according to the newly generated snap grid.

So the drawn grid is now in the right position*, but the screen (grey) is too narrow to cover the grid up.

Use COLLARDEL to delete that screen and COLLARAUTO to generate a new one.

The generated screen will be generously proportioned, but it does the job of hiding all those excess hexes really well. It will automatically be white, but I've turned mine grey again in this shot so you can see it.

I hope this helps.

*Please note that I have no idea if I'm showing the correct position as you described it, but only that the drawn hex grid is now perfectly aligned to the new snap grid.

About the length of time it takes to redraw - it might be the same or even worse after you split the polygon. What's causing the speed to drop is having to redraw millions of nodes every time you pan or zoom just a small amount.

You could use SIMPLIFY to remove all nodes that are less than the specified distance apart, and enter a value like 1 to start with when prompted. If this simplifies the outline too much undo it and try again with a decimal fraction of 1. Even if you use zero it will remove any nodes that are right on top of one another. You might be surprised by how far you can go with it.

SIMPLIFY works immediately on whichever polygon you pick. There's no "Do It" required.

It looks like the screen failed to resize. That's the most likely cause of the white vertical stripe on the right.

Hide the SCREEN sheet and see if it's still there. If I'm right and it's the screen, then two simple commands should set matters right again. First reshow the SCREEN sheet and type "COLLARDEL", then hit ENTER. The screen should have been deleted. Then type "COLLARAUTO" and hit ENTER. This should draw you a new screen around the outside of your map.

The new screen might not be the right size if you have a lot of things sticking out around the edges, but there are more collar commands explained in this article by Remy Monsen.

It's a nice easy one for all the new mappers.