Traditional Base 1 (MV & HV) is the only phase that’s endurance-only. Then (for MV) in TB2 you start to see tempo & in TB3 threshold & sweetspot.
Also, you can repeat plan phases. I did TB1 MV three times at the start of this year, meaning no intervals for about 12 weeks. I’ve done other plans in the meantime & back to doing TB1 HV right now, for different reasons than yours. It’s still only 10h per week over four workouts, so I’m pushing up the durations of some workouts & adding one ~1h sweetspot workout per week (via Train Now) plus strength training to keep touching up the type-two fibres.
I remember from a podcast years ago, Jonathan was saying something along the lines of traditional base low volume plans being beneficial only for those recovering from injury etc., because it takes a lot more volume on those plans than on the other plans for athletes to get faster.
Otherwise if you have some history on strava &/or garmin, you can sync those to TR & it’ll have some data to analyse before building a plan for you. In terms of what’s possible with the new plan builder vs what you’re asking for, you can tell it to give you only two interval workouts per week & you can shorten them right down, then extend the endurance rides to approach what you want.