extend 'terciary' energy priority into input and output

[pofigismo]

I'd like to be able to set an entity in the transformer mod (https://mods.factorio.com/mods/Penguin/transformer) to have the smallest priority - that is to only use power when all other power needs are satisfied. The problem with this is that I need an input-only connection, but as terciary is both input/output for the accumulators to work - the accumulators simply stop working when connected to an entity that shares the terciary priority. Any chance of explicit terciary-input and terciary-output to become a thing?