Vostro 3670, install optane memory, 8th generation i5

My desktop has a 1TB hard drive and I would like to install a 16GB or 32GB Optane memory module. A few questions:

1. Has anyone done this and has the experience been simple or difficult? Any hints to avoid problems?

2. Is 16MB enough for business use or would 32GB be worth the extra cost.

3. If I installed a 16GB module would it be simple to switch it to 32GB later?

Thank you for your help!