I import my files with a custom filename.... the last 2 segments before the file extension are sssss_cccc. sssss is a unique number, incremented by 1 for every image imported to my catalog and ccccc is the sequence number as created by the camera.
I have comfort in having every image in my catalog with a unique sequence number, as this avoids duplicate file names. Also, when people refer to a filename I can immediately find the image and project it belongs to, using standard Lr search tools. But, regularly, having the camera sequence number has saved me hours and hours of frustration. It is useful in a variety of situations.... especially when cards get mixed up (happens when more than one person involved in a project). Today, in a remote location I allowed another photographer use my card (should never happen, but it did), which ended up with my images and another photographers images on a single card. I was able to use my normal workflow to import the images, then recognise the images (in Lr) which were not mine. I was then able to copy the other photographers images from the card (before I formatted it) and send via We Transfer.
I spent a long time trying to make sure the original filename stayed inside the metadata, but having my unique sequence number and the camera seq number as part of the filename has proved the most useful strategy for me.