Use a concise, neutral script that makes the trade-offs explicit. Quick check on priorities: I have Task A, Task B, and Task C all marked urgent.
I have about five hours of focused time today and my estimates are A two hours, B three hours, C two hours.
Which two should I do first to maximize impact, and which can slip to tomorrow? If I start with A and B, C will likely deliver tomorrow at noon. Does that work or would you prefer a different order? If you cannot reach them, propose a default order and a time to object. Unless I hear otherwise by 11 a.m., I will do B then A, and start C tomorrow. Ask if any scope can be dropped and define success criteria, for example slide outline only versus full deck. Follow up with a short recap in chat or email to confirm the order, deadlines, and what might slip. Doing this consistently sets expectations and gives you cover when something slips.
This is stress cracking from brittle plastic plus temperature swings and oils. The cracks start at thin spots and cutouts then spread with every flex or drop.
Go for a flexible elastomer with a thicker bumper around the corners and no sharp edges near openings and it will absorb impacts instead of splitting. Wipe grit and chemicals off at the end of the day and do not keep snapping the case on and off, and avoid leaving it baking in the sun or freezing in the cold. Not a defect. Physics.