Is "run without the battery/battery compartment cover" still your advice given my Dell Inspiron setup?
Your observation (open compartment when battery is removed) is accurate for many machines.
Your concern is also accurate.
The battery compartment should be inspected and cleaned with compressed air, before replacing the battery.
In older Inspirons, the battery removed from the front edge, leaving a huge "ugliness factor" when the battery was removed. (but that is a No-Big-Deal factor)
With newer Dell laptops, the battery easily drops out from the bottom. However, the battery compartment has various "openings" into the laptop case, especially around the plug/connector. These "openings" could be entry point for dust/debris being drawn into the machine's case. (thus a clean, flat, hard surface becomes an important consideration again)
Surprisingly (to me) large numbers of folks buy a laptop for its mobility convenience, but then place it on a desk or work area and never move it during its lifetime. Additionally, they don't think about the battery/heat factor, and just continue merrily using the machine, and mostly with good result.
Does "heat" really affect a computer and possibly reduce its lifespan? Yes, of course.
Does lint, dust and debris affect a computer and possibly reduce its lifespan? Yes, of course.
Do some batteries have greater risk of producing heat and even more severe risk? Yes, of course.
Is it a requirement to have a battery installed in all laptops when running on A/C adapter power? No.
So what is to be done?
The laptop owner/user should consciously and intentionally evaluate the cost/benefit circumstance of their own machine for removing or leaving in the battery.
What do I do with my Dell laptops?
I remove the batteries when running on A/C adapter….. always.
Should you?
I can't answer that question.
It's up to the owner/user to evaluate the cost/benefit factor.
Could I tolerate the use of a laptop with a battery installed all the time?…
My Son purchased a very nice Dell laptop.
He refuses to remove the battery, mostly as a matter of convenience.
He moves around alot, and switches from running on battery vs A/C adapter frequently.
It's up to him. He bought the machine. He maintains the machine. He'll buy the new one when necessary.
Did I require that he check his battery's serial number against the Recall List? Yes.
Best Regards