Best way to add in some 'extra' while doing a low volume plan

Following the Low volume traditional base plan over the winter, planning to do I, II and III.
However, part of the reason I do low volume is to leave room for outdoor rides, lately where I haven’t been doing much outdoor riding I have been choosing alternate longer or harder rides and throwing in extra rides. In terms of the adaptive training is one better than the other?

For example tomorrow I have Fletcher scheduled, endurance 4.1 1h30m, 65 TSS, 0.66 IF, 763kj.
I was planning to instead do Klammspitze, endurance 4.5, 2h, 85 TSS, 0.65 IF, 1008kj. My endurance level is currently 5.6 so both are achievable. Is there a problem with doing this? I would think it would make more sense than instead doing Fletcher and then Totten Key endurance 1.0, 45m, 21 TSS, 0.53 IF, 308kj.

Or should I instead do the scheduled workouts and throw in a workout on a 4th day? I don’t want to over extend myself or mess up the plan but if I strictly follow the plan I’m only getting ~4.5 hours and would rather be 6+ hours per week.

I add an endurance ride on one of the off days (Wednesday for me, but could be different if you changed the schedule). That way I’m still riding at the same time of day as the structured workouts that are part of the plan.

tough question to answer not knowing your training history, usual weekly volume etc. what are your goals? can you race or add some intensity?

Started riding summer 2020, raced in 2021 (only 2 races in my area), 2022 raced XC, gravel, road and CX.

Got a trainer at start of 2022, started TR this spring (mid-April) with low volume adaptive plan to target XC race in June and Road race in September.

Heres how my TSS has been

Race season is over till the spring, could add intensity, was wondering if I should stick to the prescribed endurance work and throw in a weekly threshold workout. Right now while in Trad Base I am starting to work 2-3 gym sessions per week again, haven’t been doing much resistance training since spring.