derei

Guys, this debate became way too generic. There are two types of interruptions: short (milliseconds - seconds) and long (minutes or even permanent). Two different approaches for two different situations:
if interruption is short, that means is most probably "sleeping" and it needed a wake-up signal, or it was a short network drop, or something else. But this also means is back in no time. So, after the first failed attempt, the software should warn the user, WITHOUT CLOSING THE DOCUMENT and the user can check the connection of the drive (in explorer, for example) and then try again to save. if interruption is long or permanent (someone simply unplugged the drive, or internet is down), there isn't much to do. Obviously the document has to be closed, but maybe a better recovery system could be implemented so all tools and operations can be recovered since the last successful save on the disk. Now, as long as there isn't any "observer" or "listener" to check connection continuously, I see no reason why there would be any negative impact in performance. Just don't close the document until the user performs another attempt to save. Keep everything on stand-by and there is a very big chance that the connection will be re-established with the help of the user. I really don't see where is the issue here, conceptually speaking.

Also, having a cached copy locally would be a safety measure, a redundancy point. Yes, more space occupied on the local disk... and I see no problem with that. The storage media is meant to be used. I'd welcome a setting in Affinity to allow me to decide on which drive to create a "cached copy" of the current documents. I'd be happy to reserve ~10GB or so for that, when Affinity software is open, just to make sure my files are safe. Of course, there are issues here: what if you have Photo, Designer and Publisher open at the same time? Well, whoever wants to do graphics they usually invest in a decent machine with decent storage... there has to be a compromise anywhere.

The problem with a lot of so-called "proper" fixes is they break things more important or useful than whatever they are intended to fix. <Insert snide comment about Brexit here>
EDIT: Dang! @derei beat me to it. 

Are you a designer or programmer?  If the latter, you're in the wrong place.  You are here among VISUAL DESIGNERS.  That means we go with what we see, not with what theory or scientific data says to us.  If something looks sharper to my graphically trained eye (with Photoshop and Illustrator experience that spans the entire life of those products), then IT IS SHARP.
 
PERIOD.

Since no one knows what the difference is between Lanczos 3 "separable" and "non-separable" may I suggest that Serif put something more meaningful and descriptive into those parenthesis instead?
 
In my testing, Lanczos 3 (separable) enlargements and reductions a tad sharper than Bicubic, and Lanczos 3 (non-separable) is much sharper.
 
So I would think the Resample popup should read as follows:
Nearest Neighbor Bilinear Bicubic Lanczos 3 (sharp) Lanczos 3 (sharper) Because, quite honestly, "separable" and "non-separable" may appeal to the left-brainers, but isn't Affinity Photo appealing to our right-brain creative side?  Yes.  So make the descriptions more understandable, please!

Hi @derei,
Welcome to the forums. 
First, you have to have Rulers on ( View > Show rulers )
Next, you can drag from the ruler's divisions: from up > downwards (for horizontal guides) or from left > right for vertical guides
Thanks,
Gabe. 

using the move tool ...