I have some self imposed limits such as no rides greater than 90 minutes. As such I can do SSMV but General Build has to be LV.
To ensure the TSS and ramp rates are consistent should I add another ride to the Sunday? Would repeating the midweek ride be suitable or given the increase in intensity would it be best to add something like Baxter?
Adding low intensity to LV is super common. Lots of people do LV, even though they have the time and ability to do MV or HV, so they can do a bunch of unstructured outdoor riding and still get a good structured progression in.
I wouldn’t repeat the mid-week ride; Baxter or even sweet spot would be a better bet. LV has all that intensity because the volume is so low. If you look at MV, the primary difference from LV is more low intensity work. The tips for each week even suggest endurance rides to swap for the long sweet-spot ride on weekends.
You could alternatively do MV and knock that long weekend ride down to 90 minutes. There are lots of 90-minute sweet-spot workouts in the catalog, and there are some 90-minute options for those weird group-ride simulations: