Just guessing here from past experience & how the ECTA does things...
Usually by 5-6pm on Friday most tech volunteers call it a day. Friday's tend to be a long day & the volunteers wear out after a while!
Tech can be done any time but remember that a lot of the volunteer techs also race so if you can get in before racing starts you'll have more available techs. If you get in after racing starts you may need to wait a little longer for a tech (or 3 if necessary) to be located. Fear not, you'll get teched and be able to run if you pass you just need a little more patience after the racing starts!
Unless they have a good pool of techs not multitasking, but i wouldn't count on that!!
Get there as early on Friday as you can to set up & go through tech especially if its your first time. This way if you need to tweak anything to pass tech you'll have more time to work on it & reinspect and a bigger pool of less busy racers to advise & help out!
Good morning from beautiful Presque Isle Maine!
Debbie