Good news! Yesterday our Windows 10 2004 systems received the September 2020 Cumulative Update KB4571756. It contains a repaired MS Jet Database engine which no longer has the database growth problem. Per our resident Windows System Wizard, William Bristow (in separate posts yesterday and today, thank you sir!!):

Quote Originally Posted by William Bristow
For Windows 10 Pro build 2004 the pertinent update number is KB4571756, Cumulative Update for Windows 10. This is quite a large update and does require a reboot to complete the installation.

Other operating streams of Windows 10 may have their own particular #KB number but all versions except possibly the long service branch should have this update available for download now.

You may have to carry out a manual “Check for Updates” every day or so to force Windows to download it (or go to the Microsoft update centre and download manually the appropriate x64, x86 or ARM64 update installer), but normally these updates are rolled out to machines according to available bandwidth on the Microsoft servers and as there will be many more older machines that still have Windows builds 1903 and 1909 installed then these older machines will be be a few days (or weeks) behind the less populous latest builds, it doesn’t have anything to do with your machine being a Dell computer in particular.

Windows updates are available for manual download from Microsoft’s Update Centre usually within 24 hrs of release and checking this morning at 9.00 UT I see that the update for your machine is available for instant download if you don’t want to wait for the automatic download to reach you.

When you do finally receive and install the update you will still need to compress the database one time manually, the update itself only fixes the growth problem, it does not in itself re-compress an existing (bloated) database.
Here's an article explaining how to manually force an update.

A separate email notice on this will go out soon. What a relief!