Another problem with bring Technomancer to 4e (and not just in term of TL) is that things have changed so such from 3e. Take Technomancer's comment on page 77's sidebar about it not using Voodoo's (Later Spirits) Ritual Magic system. But in 3e ritual magic was not driven by mana nor Magery. In 4e Magery (Ritual) and Power Investiture split aspects of Voodoo's magic system: Power Investiture took the idea of eliminating mana (but replaced with Sancitity) while Magery (Ritual) took the path mechanics but retained the mana requirement.
So in 4e terms wouldn't magic opperate differently on Merlin? If they could wouldn't demons grant Power Investiture and even with they can't there are still Demonic Contracts and Black Magic (M156) to contend with. And if there are demons running around giving out such contracts then why as per an In Nomine crossover idea would there not be angels with Angelic Contracts and White Magic? These things would royally mess up the TL scale.
If you really want to mess things up you can have Technomancer-like worlds where the manafall happened for a different reason and much earlier.
Halley's Comet in 1910, the Tunguska Event of 1908, or the 1178 astrioid hitting the moon resulting in a high mana zone centered at Canterbury. These settings will have really different TL for our own world and odds are events will not happen per our world.