I agree with the potential demand for e-trikes, in that it will continue to grow in two market areas: 1) Transport and cargo. 2) Disabilities and, or aging in mobility, for health and recreation.
In the US trikes such as the Schwinn Meridian are (sometimes) available for mid-drive conversions. The tires, saddle and grips need to be upgraded immediately. These are inexpensive trikes and do not have a rear differential so only one of the two rear wheels is driven which means that they will turn faster in one direction than the other, which is weird at first. I will be doing an aluminum seven-speed when it arrives in early August for a woman who has balance issues and still wants to ride with her husband and grandchildren. I helped her purchase it on Prime Day. When it arrived a few days later it was a one-speed, not a seven. The return was free and they are sending the correct trike for the same price. The box had the UPC and photo of the Al-7, but the bike had no shifter, one cog and no derailleur. It was something like $360. Is it an ideal trike, No, but it is 1/10th the money and does 90% as much has a high-end adult trike for an older, slower rider. By the way, when the single-speed arrived I looked at the same bike on eBay and the price there was $1,200.
An elderly physicist uses one of these mid-drive torque sensor Meridians to transport satellite equipment across campus in the large rear basket between the wheels.