As far as I can see from NovelUpdates, both the WN and the LN are complete. The publisher for the LN is Kadokawa and they usually have a good track record for licensing stuff out of Japan.
I honestly don't know any manga reader that does that, particularly considering that upscaling is relatively intensive. What about getting an old Samsung tablet with a 2084x1536 resolution? A Galaxy Tab S5 nowadays is quite cheap and still powerful enough.
Just noticed that the TL skipped a chapter, plus several pages are missing.