Its a nice bit of tech. 73M in construction costs. The focal plane instrumentation alone weighs 10 tonnes. It includes 5,000 small computer controlled fiber positioners. The entire focal plane can be reconfigured for the next exposure in less than two minutes while the telescope slews to the next field. The DESI instrument is capable of taking 5,000 simultaneous spectra of different Galaxies

These are the massive black holes that lurk at the core of most galaxies. Like the one at the center of our own milkyway galaxy. The question remains do they form at the center of baby galaxies or are they the seed which triggers a galaxy to develop and they just grow even larger over time. If early galaxies had massive black holes for their galaxy size, that suggests the last option. Primordial black holes that is ones that were formed in the big bang have been a possibility for a long time. They have been talked about by astronomers since the 1970s. It great that so much is being discovered now. Lots of surprises still coming I suspect. More info on primeval black holes here. https://physicsworld.com/a/concerning-primordial-black-holes/