Unfortunately I have no control over how quickly heat-pipes themselves can transfer heat. The only possibility would be to try and have a much slower transfer rate with an internal hidden entity that goes between the infinite heat-interface inside, and the connection outside, and acts as an exhaustible buffer that cannot sustain a constant 1000°C throughput.
No promises, but if it ever works I'll update it as such, might be nice to balance it that way.
In the meantime, you can simply have the Thermal Tap on a lava source about 30+ tiles away from the consumers, i.e. Heat-Exchangers or Thermal Plant.
