[#4243] Tweaks to the new var-dumper component

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.6
| Fixed tickets | none

Hi guys!

This follows after #4243 - the best way to review it was to merge, read from scratch, and make these final tweaks. As always, I've certainly made some mistakes, so I appreciate the review.

Thanks!