In March 2018 I did the Ramp Test (Ramp Test X as was) and 20 Minute Test one day apart, the results differed by 1 watt.
I think it’s healthier, psychologically, to accept the number and move on. You get to test again soon! Better to be HUNGRY for that next test, to smash it in the face, than dreading it because in your heart of hearts you know you cooked the books on your last FTP. The latter is all the more likely if you manually crank up your FTP now. Accept the test result, train accordingly and be at peace. Once you start fiddling with your FTP on feel, rather than on objective test data, it will be hard to go back. By doing this you take on a terrible responsibility, given how passionate we are about our sport and how much of our self-esteem and identity is grounded in our performance and participation. I’m sure some riders are ready for this responsibility but I wouldn’t be in a hurry to join them (I’m not). You take responsibility for following the plan and let TrainerRoad take responsibility for your FTP estimate as long as you can, that’s what you pay them for.
The worst case scenario is that you over-estimate your FTP, grind it out through your next plan (I don’t think you said what plan you have in mind), just about surviving the OUs, perhaps turning them down telling yourself you’re on a bad day, then make yourself ill, over-tired or really demotivated. That is not how you want to approach your next test.
My other observation is that at a glance (I haven’t done it) SSB 1 Mid Vol looks to have less intensity (albeit more volume obviously) than SSB 2 Low Vol. SSB 2 LV (I have done it, this year and last) is HARD. By the time you hit week 3 you are doing Tuesday VO2, Thursday Threshold, Saturday Over Unders. That format is repeated for four weeks until the recovery week, which is a longer ‘loading’ period than any of the build plans (three weeks, always) and that’s after week 1 and 2’s Sweetspot/Threshold workouts. By cutting from SSB 2 LV across to SSB 1 MV perhaps you have taken your foot off the gas in terms of intensity? Perhaps not the best approach if raising that FTP number is your priority? After all that’s not the intended plan sequence. But as others have said you’ve been broadening your base, durability, whatever you want to call it. Feeling a lot stronger on the trail sounds good!
If you want your FTP number to go up, you’ve already completed 18 weeks of base, cut across to one of the build plans. You could even go back to LV, spend an extra day or two with your feet up, or fill those gaps in outdoors or recovery week TR workouts. Good luck in any case!