I need recent research - iPad in Education

I have been running a BYOD iPad Academy of between 100-700 students for the past 4 years at a medium-sized high school (~3000 students) where students have between 2-5 classes that incorporate the iPad. I teach 6 iPad Biology classes, and, besides the physical tests (the answers are on the iPad), I pass out zero paper; everything is on the iPad. Starting 2 years ago our district has been all Google; investing millions in Chromebooks and pushing Google Classroom, the Google Suite, etc. harder than they have done anything in technology ever. The Chromebooks are our district's answer to all of the online testing which requires every kid to have access to a computer with a keyboard. With that some of my fellow iPad teachers have been splitting time (mostly English teachers) between the Chromebooks and iPads. They have all sorts of reasons from Google Docs not being so iPad friendly - getting better though - to the "need" for a student to use a physical keyboard. Some may jump ship next year because of it.

Anyway, most of the studies I have seen are at least a couple years old and we all know that 2 years in this tech world is an incredible amount of time.

I need help. I already have the reasons for sticking with the iPad for annotating, drawing, all of the voice capabilities, ease of use, etc. but need real research that hopefully shows that students who use the native iPad keyboard can produce the same quality work that those who use a full-sized keyboard can produce. Indeed I had one of my main English teachers tell the kids "the work on the Chromebooks with a physical keyboard is just better." Anecdotally I am sure she has some experience with the quality of the work that is turned in, but, being a science teacher, I prefer a little more evidence. Because it is a BYOD program we cannot require students to purchase an external keyboard even though they may be inexpensive and I do not think that is the answer.

Some of the teachers we have on board wanted in from the beginning and do create content and curriculum specific to the iPad that cannot be done on a Chromebook, but others are wavering. I need to keep the team together and remind them why we use the iPad, how much better it is than other devices, and if you have any current research that shows any of that I would really appreciate it.