Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Dear respected Tristan Gilbert1,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
As per your description, it seems that you want to Edit files within the Microsoft list without having to download the file and after fillable then again upload into Microsoft list.
Based on my different test and I did a lot of research, I'm sorry and I'm afraid to say that there is no out of box feature to achieve the requirement.
We feel your pain due to this limitation and we’re really feel sorry for it. Regarding to your concern, I request you, please send/provided feedback to related Microsoft list/ SharePoint list l development team via Microsoft List feedback portal, so that they can get notice about it,
We can expect this feature to be used in the future in Microsoft list/ SharePoint list.
Appreciate your patience and understanding and thank you for your time and cooperation.
Sincerely,
Waqas Muhammad