Loomio as a Groupware SAAS
I know Loomio from his start, I sponsored it and I translated it into italian. I don't know in deep how Enspiral works but I imagine that the business model change is related to the economic sustainability of the developers' group. Because I like your project, I wish to propose some enhancements to make Loomio the killing app into the groupware world.
Basicly I propose to transform Loomio into a complete groupware which is proposed to the public as a SAAS, free for basic use and paid for enteprises and communities. To do that I think you need to add some features already used into other open source softwares.
I think actually the Loomio UI is not easy to use. It's not intuitive. All the user functions are on the central column. Imho you need to rewrite the UI. I propose you to adopt as UI the ones used on Humhub and on Flarum. Please do not use popups!
The Humhub UI is based on a main group with subgroups called spaces. To the main group or to the spaces, the group administrator can add free or paid modules. All the user functions are situated on the left column and that enhances greatly the usability.
For the messages' stream could be adopted the Flarum UI, that's basicly a Discourse UI simplified.
Modulization and Marketplace
I think you need to move some features to modules and to make them free or paid on a Marketplace. That's the Huhhub approach. Modulization facilitates an eventual third party development. Humhub has great modules like Etherpad integration and OnlyOffice integration (the open sourced version of Google Docs), that's fundamental for workgroups. IMHO all the Humhub modules have to be used into Loomio and decision tools have to be transformed in modules. Also plugins and integrations have to be offered on Marketplace.
I think it could be better to internalize billing process to make possibile a feature enhancement. I propose to make a new feature, that's strategic for groups: Fundraising. You could reuse the features adopted in the open source software project called Open Collective
External plugins and integrations
Usintg the planned SAML SSO authentication could be easy to develop external plugins.
I propose to make plugins for main open source CMSs (Wordpress, Joomla, Drupal) with the adoption of business model described below.
I also propose to make integrations with corporate groupwares (Slack) but also with open source ones (Mattermost).
Online paid courses
I think that Training feature offered on the Pro plan could be extended also to the Community plan and offered as a facilitation online paid course. IMHO is needed to spread the facilitation practices for groups and Loomio can act with online courses adopting a structure similar to the Training for Change one, on the enterprise and community levels both.
I wish to propose you the business model based on the one adopted by Humhub, integrated with the Loomio needs. I think you have to develop two instances of Loomio, one dedicated to enterprises and one dedicated to communities. Each with different modules. Each instance will have his prices' plan. But please reintroduce a starting free plan.
Basic: One main group with 5 users, 500 MB of storage space for an unlimited time, free of charge, hosted on a subdomain like groupname.loomio.org. The Free Plan can be updated to Enterprise Plan or to Community Plan.
Basic: Pay per user monthly. All the Enterprise instance features, hosted on a subdomain like groupname.loomio.org
Advanced: Pay per user monthly. All the basic features, custom domain, enterprise authentication (LDAP, MS Teams, OneLogin)
Basic: Pay per user yearly. All the Community instance features, hosted on a subdomain like groupname.loomio.org
Advanced: Pay per user yearly. All the basic features, custom domain, community authentication (SAML SSO)
If you're interested in planning such big change I will propose some other ideas.