Y to PE upgrade voucher then use more miles to upgrade to UC

Am being a rather dense bear at the moment so indulge me!
I have a Y to PE voucher and want to go to SFO so that’s 30k miles (off peak) for the economy seat to get me into PE if I use the voucher.i think I just need Y availability or do I need just PE?
The upgrade table then says PE to UC is 67,400
So I make that I need 97,400 miles in total.
So Peak would then be 50k + 77,400 = 127,400)?
Is that correct or have I miscounted on my paws?.
And would I just need UC reward availability (I’d do this on the phone in one transaction) or would I need it in both Y/PE and UC?
Ta for help.
I have a Y to PE voucher and want to go to SFO so that’s 30k miles (off peak) for the economy seat to get me into PE if I use the voucher.i think I just need Y availability or do I need just PE?
The upgrade table then says PE to UC is 67,400
So I make that I need 97,400 miles in total.
So Peak would then be 50k + 77,400 = 127,400)?
Is that correct or have I miscounted on my paws?.
And would I just need UC reward availability (I’d do this on the phone in one transaction) or would I need it in both Y/PE and UC?
Ta for help.