However I can not find descriptions on:

• when a certain type should be used and
• what the impact is of the related many expression options

And of course I would be very very pleased to see an example for each expression,

Just to give two examples:

• there are many SNI filter options, but it is completely unclear to be why you should not always use "ends with"
• and I did like to check if the frame to pass is SSL. So I selected type "tcp" and Expression "traffic is ssl (no value needed) but that is not excepted.
  I worked around that by just sending every thing to the default backend, but that is not the way yous should do that IMHO

So I would really love to have a proper explanation of pfSense HA type and Expression fields ......
but could not find it