Hi @DiegoF, and welcome to the community!
I do want to apologize in advance for your message being the target of one of my wild rants.
Do not take any of this personally.
Hard deadlines telegraphed to all competitors? Seriously? This is software we’re talking about here, dude! 
No one - not even the developers - know when something in the security category will be ready. Competitors would love this information as well, so you’re basically asking the company you want to bank on, to risk its existence to make you feel all warm and fuzzy about choosing Airtable. Not gonn’a happen.
As to the security features of Airtable, this aspect of the platform will never be complete, but I agree 100% - some level of improved permissions agility is needed now and more-so in the future. The vast community here has made these requirements clear.
However…
We must also consider why you are asking about these permissions features and the underlying objectives -
I get it - you don’t want to spend any more money on a visualization and dashboarding/reporting platform the likes of which is not Airtable or perhaps anything remotely like Airtable. This is a grand vision for a platform designed to collect and collaborate on data. But it’s not irrational - it’s just grand.
At the outset, Airtable’s reporting capabilities are near-flatlined [today], and you want it to get to the next level. I think your use case – while perfectly rational – is out of reach in a practical sense and not just because of the security constraints.
In my view, data science use cases require viz-ready(i) data and Airtable is not the most agile aggregation platform to make that happen. So, even if you had advanced user permissions, the pathway to analytics would still be like hiking Angle’s Landing in a 30-knot crosswind.
Another aspect of this use case is the general fitness-of-purpose of Airtable itself. To create your grand vision you must test a number of deeper requirements to see if they fit the spirit of the platform. I’m not suggesting it wouldn’t be ideal for a single platform to be the perfect data collection and management tool with a higher purpose for running your business at an analytics level. Your vision may be grand, but it’s also ideal.
The trouble is, this use case has a lot of devils in the details and the permissions model deficiencies pale in comparison. There’s nothing about Airtable that evokes comfort about a “massive base”.
But let’s say you can squeeze everything into a base that you need to effectively craft KPIs and other metrics needed to operate a moderately complex business. You still need aggregations. Airtable has rollups, but these are rudimentary and weak; you need a far different level of aggregation technology the likes of ElasticSearch.
Overall, the vision is smart, but I get the sense that your expectations don’t really fit well without aggregation into something more suitable for revealing KPIs and analytics about a business.
I also hate to toss cold water on anything without at least offering an alternative strategy, so here’s one.
Executive Base + Custom Apps
- Imagine a base for business analytics (only).
- In that base, there might be a few tables that describe the analytics a collection of custom apps might render. It may also describe target users and reports/notifications that are processed with actions.
- The executive base holds no critical or sensitive data about the analytics.
- The custom apps describe the security context based on each user’s identity (this is very secure and difficult to breach).
- Any user could be shared into this “executive” base but only users you designate through the underlying custom apps would be able to see each KPI/metric/conversation/report.
- The custom apps are responsible for aggregating the data from many other bases/tables.
- The custom apps are also responsible for rendering KPIs, metrics, and data visuals using Vega and perhaps D3.
- The custom apps are able to provide conversations between authenticated users keeping sensitive data and discussions well sequestered.
This vision is well within reach of Airtable today. It may not be financial practical for every business using Airtable, but it is ready and quite easily implemented (i.e., no technical showstoppers).
(i) viz-ready: data that has been aggregated to a level where rendering is the last step.