Downloading to Chromebook is no longer an impossibility thanks to there being a Linux terminal.
I have a Pixelbook with 16GB RAM, i7 Core, and a 512GB SSD. Obviously, have at least 8GB of RAM, but you do need internal storage.
I am going to assume you know how to install Linux on your Chromebook. If not, go to Settings, Advanced, Developers, then in the Linux development environment click Turn On. A pop up will tell you you’ll get Linux, click Next. OK, your full user name is there, change it to whatever you want. It must be all lowercase. Now, I suggest not going with the default 7.5GB, so click “Customise” and I’d choose at least 30GB. Again, you need to have decent internal storage on this. Remember, your video files are going to be in the SSD under “Linux Files.” Then click OK and wait. It’ll set up and you can go into your apps and see Linux. Open your terminal.
First, you need a flatpak.
https://flathub.org/apps/details/org.shotcut.Shotcut
Click install. Go into your Files and to Downloads. Move the flatpak to Linux Files. Click on Linux Files and make sure it is there.
In your Linux terminal enter:
sudo apt update
Nothing happens after that. Now enter:
sudo apt install flatpak
You’ll get some lines and then back to the prompt. Now enter:
sudo flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
Enter Y whenever it asks. Wait and be patient.
When you get the prompt again, enter the following:
sudo flatpak install flathub org.shotcut.Shotcut
Again, enter Y when asked and just wait. A lot goes on during these last two entries.
When it is all done, open a tab in Chrome and enter:
chrome://flags/#crostini-gpu-support
It’ll be shown as Default on the page. Open the dropdown and change to Disable.
Restart your computer. Go to your apps and you’ll see Shotcut right there in your Linux Apps folder.
I have no problems using it, but I have what was the best Chromebook of 2017. I do edit 1080p without issue. I do have to use proxy files for 2K through 4K, but I don’t have a problem.
To reiterate: your Chromebook needs internal memory and some decent specs to work, but it can be installed on Linux.
Oh, remember to move your videos into the Linux Files. When you open something, Shotcut only looks in there. Power users can set it to go to Drive or whatnot, but I am not there.