I have a HDBASE T installation, where their is a mix of Class A and B receivers feeding from a Class B distribution amplifier. is their any compatibility issues, providing the limitation of Class B are meet
HDBaseT was designed to ensure that different Classes can interoperate. Of course, any limitations imposed by either of the Classes will be reflected on the link. For example, Class A supports 70m with a 4K/30/4:4:4 format, while Class B supports 35m for the same format. Mixing the two Classes on the same link will, therefore, result in 35m support for that 4K format.
It goes without saying that you should only use certified HDBaseT products, and these can be found in the listing on the HDBaseT Alliance website. You can use the data shown in the listing to check compatibility for other features (such as IR support, RS-232 support, etc).