The EHS is a ASHP system, typically used in the retrofit of existing properties, as a replacement for gas boilers. The EHS is one of a growing number of systems that is able to provide upto 70c for heating purposes and therefore suitable for older existing rads. The EHS is not a Hybrid system!
It looks like they completely ignored what you requested.
To become MCS certified takes only 4-6 weeks, then you need to join a certification body and a chartered trading standards body, so anybody can essentially become certified in little to no time and there are cowboys in the industry!
As your serious in having one fitted it may be benificial to look for someone who is previously qualified in electrical or gas work, such as NICEIC, NAPIT or Gas Safe registerd as their overall knowledge will be superior. For example I’m a qualified NICEIC registerd spark, so it made sense for me to be registered as a MCS installer through them.
You can check on any of the certification bodies websites if they are qualified in other aera’s (bottom of page in link below) or whether an installer has just jumped on the bandwagon with renewables.
https://mcscertified.com/installers-manufacturers/becoming-certified/#cert_bodies