SteveMose

Good luck getting any other response than "the developers know, this is not an easy fix, it is on the list, blah blah blah" as soon as my current contract ends, where I unfortunately have to use this software, I will be out. There are a handful of great features in AD, but too many core flaws for this to be the single software solution for anyone who relies on precision.

I think they are more concerned about launching tablet versions than actually fixing their main product. You cannot tout UI software which fails in a primary requirement for UI design. The auto-response from moderators is very disheartening. 

I spent 2 hours trying to get 9 artboards and all their background layers all aligned so I could export to the right size rather than 1 pixel bigger than it should be with a transparent edge. This is not OK as a workflow. There are tools like Sketch that make pixel alignment very easy and there is a button where you can select a object and say snap to pixels and bam no sub-pixels. 
In Affinity even though the property panel looks like it's on the pixel boundary 780  it isn't because if you turn on 3 significant places on the pixels display (trick I found in forum on this issue) it's actual 780.029. I don't want to have to wrangle to 3 significant places to get my art aligned for export! Nor do I want to have to be worrying about 100ths of a pixel cluttering my property display.  If the force pixel alignment is ON then it should never allow a layer to be off the pixel grid when creating or moving it and ALL X/Y should be integral. 
I have to admit I was a big fan and advocate to other UX designers of this product until now, but it's such a ridiculous thing to implement as it is that I have lost a lot of faith in it.
Stop adding new features and fix the fundamentals you are being told about by professional designers. Or stop claiming this is a professional tool because it clearly isn't. Because for all it's excellent parts it let down by flawed thinking in the fundamentals. I'm not the only voice here there are many threads here on the same topic from professional designers. 

Sorry I don't see how this could be any simpler to be honest. If there is an option that says "Force pixel alignment" I expect the program to force alignment to whole pixels, period.
For types of work where you want fractured pixels you would disable "force pixel alignment".
Anything but 50.5.
Otherwise you'd have to rename the option to "Try aligning to pixels if it's convenient". In that case please add another option "Mercilessly force pixel alignment" for web designers.
Cheers

I think they are more concerned about launching tablet versions than actually fixing their main product. You cannot tout UI software which fails in a primary requirement for UI design. The auto-response from moderators is very disheartening. 

Let me start by saying that I am a huge advocate of Affinity products and I own Designer and Photo for Mac and iPad. We're coming up on 4 years of having this bug (critical IMHO) and all I still see is @MEB's copy-pasted response from years ago. Now I get that this is a harder bug to fix but it seems to have been completely ignored. And if it has been ignored, I think it's very misleading to have the word 'Icons' listed on the website. Even 'pixel perfect' is quite misleading considering this bug. And as people pointed, there are free and cheaper vector apps that handle Expanding of strokes far more gracefully than Designer does. Many icon designers purchase this as an illustrator alternative and as it stands today, Designer is NOT suited for icon design.
I completely agree with @Xavez's comments above. This is definitely a major oversight!