I have had a knee issue for the passed 7 weeks and am now cleared for training. I was wondering something similar.
My plan is to complete SSB LV1, then at the two week mark introduce long outside aerobic rides on Sundays. Then when complete I will move on to an altered version of SSB I & II somewhere between MV and HV.
I suspect my injury may be more significant that yours (purely based on the duration) hence the conservative return.
I have completed HV before, I would only advocate trying the HV plan if you have completed it before without injury and with high adherence to the plan. The plan is significantly harder than MV.
I guess the question is whether the risk of rushing your return to the sport so you can perform better at the Grand Fondo in June is worth the chance of prolonging your injury? That’s something only you can answer.