I was in a similar position to you but took a slightly different approach although similar to what @trpnhntr and @chad suggested. I should say that I am primarily a long distance triathlete so all the TT’s I rode were training rather than a focus.
I followed the base and sustained power build high volume up to the season last year coming into the TT season and raced twice a week through the year, a 10/15/25 midweek and a 25/50/100 at the weekend. My feeling was that the races I was doing weren’t dissimilar the the training in some of the TT and Triathlon plans so I didn’t want to replicate that elsewhere in the week so I cherry picked from some of the other plans rather than follow one completely.
What I ended up doing was working my way through the Tuesday and Thursday workouts from the Climbing Road Race plan, one per week, and a longer endurance ride alongside the races and any easy 30 minutes before my interval run each week.
That gave me 5 rides a week roughly as…
Tue - VO2 Max session from the Climbing RR plan
Wed - Midweek 10/15/25 mile TT threshold work + WU+CD
Thurs - Volunteer - easy 30 mins as a WU to a run
Friday - Long endurance ride - longer if the weekend TT was a 25, shorter with a 100 mile TT
Sun - 25/50/100 mile TT + WU and CD as generally Sweet Spot/tempo session
The days sometimes changed but for a lot of the race season it worked well. Because I was only doing one of the two sessions it took most of the TT season to work my way through the Climbing RR sessions.
I felt that given my racing was a lot of Sweet Spot/Tempo/Threshold work that wasn’t something I needed to replicate in training and the variety of adding in the VO2 Max stuff from a different type of plan was a different stimulus both mentally and physically.
Obviously you are focussing on shorter distances than I race but there are lots of ways to use the training plans within TR to your advantage rather than feeling you have just to follow a single plan. Inevitably the plans are aimed at a single race or goal rather than something like the UK TT season which means racing a lot over a 4/5 month period knowing that a PB often relies on a fast course and weather conditions combining. That could be an any point in that year and you never know when!! You’ve just got to be ready to take advantage whenever it comes.
I’m sure that following one of the existing plans as written could work well but there a loads of ways that you can manipulate them to suit your racing schedule and could also fit in with your idea of maintenance during the racing season.
There are plenty of workout progressions within the existing TR Training Plans for you to take and work with as bases for you own personal trajectory and is one of the real benefits of the TR plans, system and workout library.