Gestalt has a pretty lenient death system. Whenever you completely lose health, you respawn back at the last tether save point (or other story checkpoint, in some cases), but you still keep some progress you made - all experience earned, items gained, story beats triggered, etc. We can take advantage of this to warp back to specific save points to save a little time.

Fornax Death Warp Skip

In Fornax, there's a phase where we need three different valves to progress, and we need to sidetrack to three different areas for each one, backtracking to a main central room each time. The backtrack isn't terribly long, but we can shave a little time off of that by death warping back after each valve instead.

Scrap Sea Death Warp Skip

We can do something a little more complicated and save even more time with a death warp in the Scrap Sea. Normally we would head deep into the Scrap Sea, defeat the Raider Brute boss, collect the charge shot and then backtrack to Faria's hut. Since dying respawns us at the last save tether we've actually activated, though, we can manipulate that a little bit to skip that backtrack process. If we skip out on the save points on the way to the Raider Brute, defeat him, and then lose all our health immediately afterwards, we'll death warp all the way back to Faria's hut and skip through a good chunk of backtracking.