This is great! I will definitely try this out when I get the chance and follow development.

For the last year or so I had been thinking of a similar thing and planning to write a post on r/datahoarder about it, but decided not to because as someone who knows nothing about software development I would be basically just asking people to create an app I want for free.

Here are some random thoughts I had had for that app:

Import from multiple sources WhatsApp/Signal/Telegram/etc - either from databases,backups, exports, or just parsing text files for if you are able to compose a chat history in any other way. Optional chat merge - merge chats from different sources into a single chat history instead of into a separate chat isothere
Address book/Contact - so that you can manage things clearly when merging