There are two other key differences versus DDR4. Up until now, error-correcting code (ECC) was not mainstream for consumer applications. This changes with DDR5 as ECC is now a default feature for consumer memory. Furthermore, DDR5 will also have onboard voltage regulation. This circuitry will no longer reside on the motherboard.
Corsair says this will result in DDR5 running hotter than DDR4. The firm provided no specifics though, so we don't know how necessary cooling will be. As far as I know, there will still be DDR5 memory without even a heatspreader.
Corsair DIY Marketing Director, George Makris recently confirmed in a recent video that DDR5 memory could "conceivably could run much hotter than DDR4" due to voltage regulation being moved to the memory modules from the motherboard. This was reiterated by Corsair Memory Product Manager, Matt Woithe, who notes that they are prepared to handle this increased heat in Corsair DDR5 modules using their Dual-path Heat Xchange (DHX) technology.