@wisdomlight yes, and no. There are several options, but none of them are perfect:
Install Axolotl from the openstore. It can act as a primary or secondary device. It's currently bare bone and didn't always work when i used it as a secondary device, haven't tried primary.
Install Signal through waydroid. It works well, but you don't get push notifications and waydroid drains your battery faster.
Create a matrix bridge or purchase one. The bridge act as a secondary device and you can use the matrix app Cinny.
I currently use a purchased matrix bridge from element one, and Cinny. It works ok now after they resolved some issues with the bridge that happened earlier this year. I use signal in waydroid as a primary device, and have it as a backup in case the bridge fail ( it has been stable so far). Unfortunately I can't copy paste stuff in the Cinny app, i've opened an issue on github.