I was going to talk a bit about this in my next study log post, haha, but I feel like maybe there’d be more interest in the topic here? It would certainly have more readers 
I actually went down a bit of a rabbit hole a couple weeks ago because the library I work at had this book available digitally:
Tono, Yukio. Research on Dictionary Use in the Context of Foreign Language Learning : Focus on Reading Comprehension . Reprint 2012. Tübingen: Niemeyer, 2001.
It’s from 2001, so new research might have supplanted it, but I was curious enough about the subject, haha, I ended up skimming my way through most of the book.
Here are some thoughts
From what I read, there’s unfortunately not a whole lot of research on the difference between monolingual and bilingual dictionary use (at least, as of the time that this book was published). Overall language ability was a much more accurate predictor of how proficient the students were at using dictionaries and comprehending what they were reading. Bilingual dictionaries were by far the most popular among the students, but some advanced readers appreciated monolingual dictionaries
Many of the subjects in the various studies had their own dictionary preferences, but it didn’t seem like the monolingual dictionaries gave them a particular advantage. In one 1998 study, there was no clear task difference in the results, though the author of this book remarked that it’s possible that the tasks were too easy for them.
Of course, these studies were all testing short-term stuff, like the ability of students to complete specific tasks, and didn’t really examine regular dictionary use over a long period of time. Though it did seem pretty clear that using any dictionary was better than going without, at least in terms of general reading comprehension of any given passage and ability to successfully complete tasks. Using a dictionary provides superior comprehension compared to trying to understand purely through context.
Apparently this philosophy has at times been controversial (many language teachers focused very heavily on learning through context and discouraged extensive dictionary use), though I think most of us self-learners here are pretty lax haha and recognize the value of reading intensely and using a dictionary. You do still learn from extensive reading, but not as much as you learn from intensive reading where you make an effort to look up words instead of just guessing from context, it seems.
The author of the book also pointed out that your first language has a huge effect on the ease of using monolingual dictionaries. If your native language is very close to the language you’re learning, it makes it way easier to use a monolingual dictionary.
Of course, plenty of other stuff affects this. Like not only monolingual/bilingual dictionary, but the specific dictionary being used and the information it contains (like providing context sentences usually does more to help students understand how words are used rather than simply specifying part of speech and such), as well as the reader’s ability to know how to effectively navigate the dictionary.
I guess my conclusion from what I read (which, granted, was not the whole book, haha) is that there’s a much bigger difference in reading comprehension between reading with a dictionary and reading without one than there is a difference in comprehension between reading with a monolingual dictionary and a bilingual one, so I’ve decided to prioritize ease of dictionary use above any other factors. I want to make it as easy as possible for me to (intensively) read as much as possible. As my language skill improves, monolingual dictionaries will get easier to use, and I’ll probably find myself wanting to make the full shift eventually.
I do wonder if any new research on the topic of dictionaries and language learning has been published after the book mentioned above, and if any of it specifically addressed bilingual vs monolingual dictionaries in terms of long term benefits to language acquisition, or even addressing newer technologies like popup dictionaries like Yomichan, which undoubtedly change the entire process.
My thought is that probably no matter what you do, there will be trade-offs, and it’s just up to the individual to decide which trade-offs are worth it and which ones aren’t. For me and you, perhaps the time/energy trade-off to go monolingual currently just isn’t worth it, whereas for others in the thread, the costs aren’t as frustrating. I think whatever method gets you looking forward to reading, and which doesn’t make you dread doing your flash cards, is probably the best method for that person. Once you reach a high level, it all pretty much evens out anyway.