There are a number of other small VTOLs that have been exploring hybrid tech for the UAM market. However, the UAM market is perfectly suited to the current eVTOL capabilities so minimal money is being spent on a large scale. Where the big hybrid tech and money is being spent is for the RAM or regional air mobility market where they use much larger and existing aircraft to increase the payloads and ranges. For example, there is a Dash-8 and Dornier 228 flying with hybrid hydrogen fuel cell powered electric power plant replacing one of the turbine engines. And last I heard both aircraft will be flying with both engines replaced with hybrid electric motors this year.
Regardless, the biggest stop-gap "hybrid" change will be the use of 100% SAF fuels in the current fleet. Once that happens I think you'll see an increase in other hybrid technologies as the development monies from the 100% SAF side will be directed into those projects. Interesting times ahead.