We're building Gatherly (gatherly.io) for a similar audience but with a SaaS approach focused on professional services (accounting firms, law firms, consultants). The key difference is we've baked in eIDAS-qualified e-signatures and automated document collection workflows — so clients can sign agreements and upload requested documents through a single branded portal, no account required.
The self-hosted angle is interesting for developers, but most of the professional services firms we talk to want zero ops overhead. Would be curious if you've seen demand from non-technical users.