Custom mibs are used partally only?

Yeah I agree

I hope I have turned debugging on with my changed telegraf.conf:

yep that looks right for debug.

do I need to change something in the entrypoint to get the additional MIBS working?

Thanks for trying with the snmptranslate command. It looks like it only worked when you specifically added that file?

My guess at this point, having not done much with SNMP, is that the telegraf config either is:

1- needs the path updates to include that SNMP file
2- the config in telegraf is pointing at the wrong OID

Let’s try number 2 first. Looking at a previous table SNMP issue as a guide, it looks like you have the table at .1.3.6.1.4.1.24681.1.4.1.1.1.1.4.3, and then want fields under that, so something like:

[[inputs.snmp.table]]
  name = "cpu"
[[inputs.snmp.table.field]]
   oid = ".1.3.6.1.4.1.24681.1.4.1.1.1.1.4.3.1.1"
   name = "index"
[[inputs.snmp.table.field]]
   oid = ".1.3.6.1.4.1.24681.1.4.1.1.1.1.4.3.1.2"
   name = "id"
[[inputs.snmp.table.field]]
   oid = ".1.3.6.1.4.1.24681.1.4.1.1.1.1.4.3.1.3"
   name = "usage"

I know you had something similar commented out, but note this is slightly different in that the fields define the oids.