How to use explicit xProperties in ItemType?

I discovered following hint in the manuals:

Seems like explicit xProperties are a dead-end feature. There is not UI yet.

In my case I would be happy to display the xProperties in a custom tab (preferred) or inside the main form if there is not other variant. 
I don´t need to edit the data in the Form or Relationships, because the would xProperties be filled by REST API automatically.

As far as I see even the newer releases don´t support explicit xProperties yet. (and I am 99% sure Aras will forget them in the new UI editor they are working on).

Has anyone seen a sample implementation for the missing UI? 

Does no one know more?

Maybe anyone has an idea for an alternative concept. I have an ItemType that shall store testresults. Each test item shall store additional values of various sensors.

So basically my ItemType looks like this:

Test-No.: T-1234
Device: My product XY
Test result: PASSED

Sensor and other test data:

Back1235:   3.2V
Back1243:   3.3V
Top1234:     1.1V
xyCounter:   234234
Speed:        2599
...many many additional properties here...

I want to display the test data in a way that:

1. It´s easy to read inside the individual test item
2. Use can search and compare the values on a general level

So basically I am thinking of two ways to display the data. In side the items it would be useful to have something like the parameters tab. The individual properties are displayed below each other:

In addition, users shall be able to search through all the data in a grid. In this case, the properties could be displayed side-by-side:

But so far I haven´t found a building technique in Innovator that provides both view options

Idea 1: Parameters tab
- Pro: Easy solution regarding displaying the properties in the testresult item itself
- Con: I cannot search and compare test data for multiple items. By default my test data properties are hidden in the grid, cause they are so many. There is no way to manually unhide them for the user.
- Possible solution: Federate Parameters data in a fake grid?

Idea 2: Explicit xProperties
- Pro: This one would solve the Con of Idea 1. Explicit xProperties can manually unhidden in the grid by the user.
- Con: There is right now no option available to display the properties in the Form or in a relationship grid

Idea 3: Properties in relationship
- This helps to display the data in the grid, but looks terrible for the individual items. I would have one relationship with all properties side by side.

Idea 4: NULL relationship that looks like Parameters tab, but user can assign "Property Type" and "Value" manually.
- Good for displaying the data in the individual items, but terrible regarding building a search grid. 
- We cannot specify data types for the individual properties

Idea 5: Properties in relationship, but custom relationship Form view 
-...

If anyone has an idea to display the data the best way, I would be happy for any input :).