If you have expensive cat's resting place which happen to also 3D print stuff, I have the solution for one of your problems. My cat weights almost 6 kg and its only matter of time when he falls into my printer. Top panel maybe holds it now, but it bends significantly and I don't want to test it long-term.

I've designed grid-pattern top cover, which you can throw on a blanket for that little rascal. Top vents are accessible and not blocked. Of course it's bigger than a buildplate, so I splitted it to 9 parts. Every one of them are named like FL (Front Left), C (Center), BR (Back Right) etc. 

BOM:

1. M3x8 BHCS screw x20 - link

2. M3xL3xOD4.5 mm heated inserts x20 - link

3. 12x4 mm flat silicone pad x20 - link

4. About 700g of filament, I used ABS

5. Cat or other agile pet

6. Blanket

Printing:

• Position elements with letters facing up.

• Use supports for flat, unsupported parts,

• No need to support 45° legs,

Assembly:

1. Inserts will be placed facing up, when text is facing down.

2. Near 45° part on the inside put one silicone pad per "leg".

3. Parts descripted as FL, FC and FR have groove for air vents screws and shoud be in front of a printer.

4. Put some blankie for your kitten.

5. Remember to leave airflow for vents.

Cats are happy and I am happy.

Banana, 6 kg:

Little Seagull, 3.5 kg:

Top view of protector:

Bottom view of the protector with silicon pads: