TT plan ftp test

I am following the TT plan based on plan builder because since there are no races I am taking on a local mountain climb segment, its called doi suthep in Thailand, 10.7km 623m at 5.8 gradient. I just completed the first part of the plan and did the TT in 46 mins. I would like to get a sub 40 if possible. Is this the appropriate plan? Second question is on the recovery week at the end there is a 20 minute ftp test scheduled. Can I just do a ramp test instead as a cruisy weekend ride to substitute? Just a note my power ramp test declined 5 watts after sustained power build plan :frowning: