Currently there is no efficient means to farm this or Mutagen.
At around 00:00, the ship will warp until around 01:30, check the colour of the drops, if white, the asteroids contain mutagel and ambergris (check for a yellow/brown hue on the rocks).
The issues here are the ambergris and Voidwyrms. The Ambergris weigh 5 per object and do not stack, filling the survivors inventory I'm seconds. When inventory has reached the soft cap (max number of slots, indicated by a black, weight symbol), drop the ambergris and continue. Striders gather too much ambergris and hit the limit too fast, not good. Drill does not help either. Tames are too slow, including mantis and do not harvest as much as yourself.
According to tests, you generate the most mutagel with a max melee build and graded picks. However, it is slower than using the rocket punch provided by exo suit. Use the punch to harvest and boost up to reposition before punching again.
On Xbox, double-tap A, hold RB for acceleration (you can do this even when overburdened). After 5 rocks, drop the ambergris.
Alternatively, go to Rockwells place, located under his heart is an acid pool that rises and falls over a period of serval minutes. You can harvest here without waiting for asteroids, but the risks include reapers, seekers, basilisk, pretty much everything and the acid, with tentacles slow you down prevent boosting. You would also have to extract the mutagel and make it out alive. Summoners don't patrol around the pool, and even if caught, then can't do much to catch and kill a survivor in a jetpack.
You could try to find mutagen and convert to mutagel (or just keep it as mutagen) by find the hidden spawns inside the Rockwell area. But they are very difficult to spot. On the series X, the rendering range is very short for mutagen, plus they are very small, only betraying their location via a small glow. Your will have to land next to the mutagen, harvest, and get out the immediate vicinity as the nearest summoner will aggro in response. There can be three spawns at once, but with a lengthy respawn time, difficulty in finding and a yield of ONE. It is better to harvest mutagel, 800 can be converted to 6 mutagen in a chem bench.
The map is a ship. When the ship goes into hyper drive, the space area (the large gap in the center of the map) changes resources. The color of drops also changes. Mutagel can be harvested in the space area when the drops are white. The rocks in space also have ambergris. The color of the rocks are an orange/bronze color. The area in space has greyish rocks with cyan looking flecks in it.
You can find this in Rockwell’s garden in Rockwell’s innerds go in as deep as you can where his heart is and final mission terminal directly below there will some stomach acid wait for it to go down then it’s everywhere on there ground pick it up by hand there’s heaps of it be careful for the stomach acid rising and the reaper queens but seeing how we all have a tek suit it’s quite easy
You can find this in “the void” on the Genesis 2 map. The Void is the space area in between the two half’s of the whole map. The easiest way to get there is to get a flyer and look really high on the ship wall and find a hole/duct.
You can only find it by harvesting a brown (turd like) rock on a certain day. You never know when that day is since the void changes every 24hrs.
Inside Rockwell's innards if you follow the route down to the Heart where the final mission is, jump down and float to the bottom you should see what looks like a Stomach wall.. jump in collect the mutagel, i collected by hand as i just found it, BE warned Stomach acid starts to rise from the stomach wall and burns through armor, wait like 2 mins and it washes away, repeat.