PSD Smart Object support is great, but seems to be missing something important...or a warning?

[narrationsd]

If you try this out, as in https://www.youtube.com/watch?v=OKWEjZMGM1o or other YouTubes which show similarly, it works very well - a feature such as a geometric transform is replicated in Affinity Photo -- great. And thus you can replace the original content with another, retaining the transform, which is very useful where perspective has been created, for example, as your replacement will get the same perspective fit into the  overall composition. 

However, I ran into problems trying to do more, which seem to center on Smart Objects being implemented, but not Smart Filters. These are simply eliminated, so if you've done anything to the original using them, it's just ignored. 

A particular problem is that if you did Filter operations on a Smart Object in Photoshop, it automatically turns those into Smart Filters...so you are guaranteed to lose them.

There are probably a lot of ins and outs about how Smart Filters could be usefully handled, which will be up to your team to delve into and come up with the best that's practical.

Not having more time to play, at the moment it occurs to me that an answer on the PS side would be to create the embedded object separately, pasting it into the composition flattened. I think this is necessary, as I can find no way to successfully flatten a smart filter, Adobe having been so impressed with themselves. 

Confusing to this, you will find Flatten Image on the PS Layer menu, not the Image menu, and yet it will flatten your entire composition. As well, if you try extracting (via double-clicking) the layer, Flatten on this will end you up with a white background, so that save and close nets you the rest of your composition below the layer covered up.

Back to Affinity, I think it's probably apparent that not all Smart Filter operations could be replicated, but perhaps a useful subset that would be worth it?

Or in any case, a (cntl-C copiable) warning alert that you've just lost Smart Filters, listing them per Layer of PSD import, would seem a very usefui and easy addition to present 1.8, if you also think so?