I’m getting very slow startup times with Houdini. It seems to be looking for a Template profile. Is this something that I may have accidentally set, or is it something that should be there that Houdini cannot find?
I’m quite confident the slow startup times are not due to that - but likely due some HDA loading. But, we can investigate this! You’re best off profiling Houdini’s launch! Vrooooooooom!!! 
Check out how to profile Houdini’s startup time.
This becomes extra easy if you’re on a recent version of ayon-core because you’ll have a “Terminal” launcher action:
And then in that command line run:
houdini -profile-startup=debug.hperf
It will launch houdini with startup profiling enabled. The file will be stored in the working directory (the one from the command line) after launch finished.