Are AWS ElastiCache Reserved instances size-flexible?

I am currently looking into purchasing a bunch of ElasiCache reserved instances.

I know from EC2 and RDS, that it does not matter if you purchase e.g. a t3.medium or 2 t3.small instances, because the reserved instances are size-flexible

Is this also the case for reserved ElasiCache instances?

I can not find any hint about it here or here...

Yes! They now are, as of 1st October 2024.

https://aws.amazon.com/blogs/database/new-size-flexibility-for-amazon-elasticache-reserved-nodes/