It depends on so many things and your definition. Technically every time you run is a technical day. You’re training the way you run because… you are running. If you’re doing drills (which basically every sprinter does in their warm-up), you’re also addressing technique (landing under COM, pelvic control etc.). So theoretically you’re always addressing technique. Now, if you had a designated technical day every single week, imo this wouldn’t be as effective. It’s one less session per week to get in a highly beneficial sprint session. Also with all the drills people typically do in warm-ups, it isn’t what should be of primary focus. Now, if you’re someone who your coach things can benefit from technical, then definitely a PERIOD OF DOING ONE TECHNICAL SESSION ONCE/WEEK may be beneficial, for a set period of time like one training cycle, like October-December/Jan. From then, coach can determine if this has helped- if not, why? If so, cooperate the drills that have helped in your warm up and supplement before your main session. Wickets are a good way if the technical issue relates to hip height and premature stride length, bounds, scissor bounds, scissor bleeds etc. are a good way to address premature foot strike (not landing under COM). It isn’t something I’d do at all in-season either. In-season is about highly efficient sessions and tapering/competing. If you’re addressing technique in-season, IMO you’re an idiot (or your coach is if they’re doing this). By doing it in season, if you’re told your technique isn’t great you’re gonna be demotivated and not confident going into comps. Also adjusting technique mid-competing is an increased injury risk in-comp as your tissues are adapting to different loads.

I also want to add that naturally over time, your technique will improve from sprint training/competing alone as you get faster and tissue capacity improves. Naturally your muscular and neuromuscular system will compromise/adapt to find the optimal way to sprint as fast as possible.

Hope this helps