Replying to Full Tilt Shell/Liner Sizes 28 vs 28.5

Hi folks - I'm looking at upsizing my boots after losing some toenails last year #RIP.

I currently have a 27.5 Full Tilt and was looking for a 28 but can't find anything online (ebay, NSers, evo, backcountry etc) -- I see 28.5 everywhere for Full Tilt. I also see that a lot of the shells for 28/28.5 are the same size but does that mean that the only difference would be the liner?

If I bought a 28.5 shell and got a 28 liner would I be good to go?

Any advice from the snow gods is much appreciated - Thanks!