The last build broke the Pulse Wave Analyzer for some (most) people so Deep Core Mining is pretty much out until that gets fixed. Some people are trying to figure out ways around the issues, like flying FAO in reverse to pulse but it is still badly broken even using these stopgap workarounds.
Low Temperature Diamond mining is dead in all forms, not just a little dead but really dead. Exploits were patched, rarity was increased, and price was indirectly nerfed by changing price/demand to update in real time while keeping the initial demand relatively low.
The current meta is surface (laser) Painite mining in a known Painite 2 spot using the Miners Tool to locate the Painite 2 spots. Painite 2 means double overlapping Painite hotspots. But the recent patches have nerfed overlaps and buffed single hotspots. The yield was reduced in Painite 2 hotspots and dropping into the overlapping areas has become harder, but missing it isn't as punishing. Now mining well inside the yellow hotspot zone on a single hotspot is within a few percentage of mining in a Painite 2 overlap.
The emerging meta is RES mining Painite where the RES overlaps a Painite hotspots, so a new type of overlapping mining. Because mining within 20Km of the center of a Haz RES doubles yield and single hotspots were buffed this is the new king of income. In a High RES yield is increased 75%, Regular 50%, etc. Some RES maps with guides and videos. and more maps with pictures only.
It is also profitable to random mine in a RES without using a map by staying within 15-20Km from the center to get the bonus but minimize the pirate attacks, probably the best spot is HIP 21991 2 Ring A High RES. Other spots are Irusan 2 Ring A High RES, HIP 35219 2 Ring A Haz RES, and HIP 60953 ABC9 Ring A Haz RES.