Welcome to the forum!
I've also been frustrated with that Open Recent menu item, lately. I don't have so much trouble with imports specifically, but sometimes that happens.
I've been frustrated, because Inkscape has started putting files there, which aren't even mine, not even on my system. I open loads of files which people upload as attachments (all kinds of formats) which they need help with. I don't know why Inkscape reports them there, because I would not be able to open them later, because they aren't even in my system. Not unless Inkscape is saving them somewhere, without me realizing it??
In a busy few days in the forum, when I don't have time to work on my own projects, all of my own files get kicked right out of that menu. Then it's full of files that I would never want to open again.
And like you, if I make it any longer, it will have to scroll, and then it's kind of a pain as well. I suppose I could just start clearing the list from time to time. But I would hope for a better solution.
I think this certainly is worth a discussion!
What if that Open Recent list would only show files which were saved by the user? If you didn't save the imported image (in its original format), it wouldn't end up in that menu. Although that would leave it open for PNG exports to show up there.... Maybe they do already, I have not noticed. I'll try it....
Ah-ha! Exported PNGs would not show in a menu like that, because it's not saved, technically it's exported! And no, it doesn't look like they show up there already.
I have no idea how hard or easy it would be to implement that though.
Another problem is that if you open the same file a few times, it gets listed in that menu, every time you open it. That doesn't make much sense to me either. Inkscape must be saving these files somewhere. Because let's say I've opened a file 6 times - let's say test.svg. Then the menu would have test.svg, test-1.svg, test-2.svg, etc.
If I've been editing that file every time, by the time I get to test-5.svg, it's a very different file from test-2.svg. What if I opened test-2.svg from the recent menu? The implication is that Inkscape would have that version of the file somewhere, and it could open whatever stage the image was at that time.
I've seen the question several times in forums, over the years. "omg, I opened my file and everything is gone, I don't know what happened, is there any way to get it back" Does this mean they could get the contents back by using the Open Recent menu??
Geez, after all these years, there's still so much left to learn about Inkscape!