See my comment here: #1526 (comment). I would prefer to remove TimerOutputs from the codebase, and users can instead either use profiling or dev the package and add their own timer annotations.

This was never meant to be a user-facing feature, we only added timers for internal development purposes. I think it is a bad idea to make timers user facing because it is just another feature we have to upkeep and users will rely on, and users will inevitably want new timers added for their own purposes so it will be an endless game of supporting the current timers as we refactor the codebase (see ITensorTDVP.jl/ITensorMPS.jl/ITensorNetworks.jl where we are rewriting and generalizing DMRG in various ways), adding new timers, or turning down requests for new timers to be added.

EDIT: I also remember seeing some performance issue with TimerOutputs.jl, I think it caused some type instability, though maybe that has been fixed at this point or I am misremembering.