Peter Gamma from www.petergamma.org invested a lot of time for Libreoffice on the Pinephone:
https://petergamma.org/category/mobile-office
https://forum.pine64.org/showthread.php?tid=16614
https://petergamma.org/category/pinephone
LibreOffice is a full desktop app on a Linux phone. But we have given up this project for the time being. We have chosen Softmaker for Android instead. This app is touchable and adapted for the phone screen. But Libreoffice on the Pinephone has the advantage to be open source. Softmaker for Windows and Linux is not open source.
It is therefore worth to develop further LibreOffice on the Pinephone. We have posted this subject to the LibreOffice forum. Unfortunately our posts where deleted there. But if you want to take over this project for your own needs, we think it is worth it.