LLPT Double Sided Foam Tape 1 Inches x 50 Ft Durable Adhesive Weatherproof for Fill Gaps Attach Bond and Mount Uneven Or Textured Surfaces (T004A)

Have you heard of double sided foam tape so long as you aren’t throwing your case around should be fine and will also provide some vibration dampening for the hdd https://www.amazon.com.au/LLP-Automotive-Mountings-Weatherproof-Adhesive/dp/B07P9JC46T something like this whatever is cheaper but you get the idea