Migrate Message and iMessage History from old Mac to new Mac

Hi folks, i'm in a bit of a situation with my Message history. Currently, I've got on my hands an iPhone 14 Pro with iOS 18.2, my trusty 2017 MacBook Pro running MacOS Catalina 10.15.7, and a new 2024 MacBook Pro with MacOS Sequoia 15.2. I have iMessage set up on my old Macbook and my iPhone and am looking to copy it all over to the new macbook. I did not use Migration Assistant while setting up my new MacBook due to the differences in the OS and I also wanted to have a fresh start with regards to my files and such on my new device. I also have "Sync messages to iCloud" disabled on all of my devices (iPhone included), because I feel like I would have run out of iCloud space really fast given attachments and stuff. (Please correct me if I'm wrong on storage estimates.) I also don't trust Apple's transparency on how it syncs or backs up stuff to iCloud; it feels like a black box and a trap to upgrade to a subscription. I have heard of many a nightmare regarding syncing photos to icloud and managing them. So, I found the Messages folder on my old device with chat.db and the associated files/folders and copied them over to my new device. However, when I opened Messages, I discovered it only had my conversations from the past year, a few of the oldest conversations since I've been using iPhone (2016), and only a few from in between the two dates. After some research online, I learned that Apple changed the way it stored Message History between MacOS Catalina and MacOS Big Sur, and got rid of the "Archive" folder that had messaging history organized. Some users also reported losing some of their messaging history across the upgrade (biggest red flag for me). I am wondering if anybody knows of any tools/scripts I can use or a procedure I can follow in order to upgrade and move a copy of my message history from my old macbook to my new one. A solution I thought of was create a VM running Catalina, copy my messages over there, upgrade the VM to a newer MacOS version, and copy that set of messages to my new device. I seem to have run into some trouble there. I know I'm being stubborn for not upgrading my old macbook to the new OS. I just never felt the need or urge to, since I didn't like the way it looked when Big Sur was introduced lol. It had mostly worked pretty well for me. I am willing to give the iCloud sync solution a try only for the purposes of the migration if someone could explain what is synced/backed up, and if you can confirm I won't lose my message history when I disable it again once the migration is complete. Thank you!