I have a 1.3GB Draw file open with a good deal of artistic text, multiple large transparencies as well as 5 other programs open for a total of 6.5 GB in memory.
Selecting a 20" x 40" image at 200 DPI and using the edit bitmap feature transferred the image to Photo-PAINT for editing in 6 seconds. All edits went well.
I wouldn't doubt that it is too light for your purposes! For mine, maybe it will work. I'm not sure.
I haven't tested the 2.4 version I do know that many are voicing the opinion that the new release was way short of expectations.
I did download Affinity Photo 2 twice, V2 and V2.4, since the only feature version 1 had of any value to me was noise reduction and they screwed up zooming and scrolling in V2 I unistalled version 2.
Affinity Photo and PaintShop Pro web sites seem more geared toward digital art rather than photography so there's not a great deal of discussion of relevance technically for me.