Hadn't realised that you were moving close to T-Jay. That will make everything so much easier for you.
My first thought is really just what T-Jay has already said about moving the back sections higher up.
From what I can see in your pics it looks like you have enough space in the butt and back sections to do that.
You can use masking tape to hold the armour in place when trying different positions, rather than straight away installing new poppers.
Will be easier if you have someone that can help you.
But, you still want to keep the top of the kidney and ab lined up.
So, if your kidney moves up, so should your ab section to maintain that line.
If you are able to do that and its still comfortable to wear (I guess around the cod section mostly) then all cool.
Your chest plate wouldn't need to move as you would just have more of an overlap of the chest and ab.
Mark Hamill famously was pretty small for his armour, and you can see this especially with how close his ab buttons are to his chest plate.
My second idea is really only if T-Jays suggestion can't be done for any reason.
As you are currently wearing the armour, where the butt and cod meet is very close.
I imagine that the end of the butt plate between your legs is already uncomfortable, and it would likely cause even more problems walking around when trooping.
You could trim the butt plate shorter at this point (so it doesn't sit so far between your legs) and make maybe make it a little narrower if needed too.
In doing this you may need to remove the front most popper and install a new one further back.
(Contact RS for a new popper if needed, as not all poppers work together, even if they look the same size)
This should stop you from being able to see the butt plate from the front, as well as make everything more comfortable.
Obviously once done this can't be reversed, so (as already said) anything that involves cutting plastic should be a last resort.
Yes, this would mean there's no return edge where you've done the trimming.
My butt has practically no return edge at this point. It's not a requirement for clearance here even at level 3, and actually allows the plastic to flex a little more without cracking.
I did shorten and reshape my butt plate in this way a little, even though I'm quite a lot taller.
If doing this, drill out the popper first, as you only need to trim back to the hole, not the edge of the popper.
When trimming (as I'm sure you already know), slow and steady. Trim a little. Try it. Trim a little more if needed.
These are just my ideas to go into the melting pot.
My last thought...
Even though you have the uncertainty of the move coming up, try not to be tempted to rush to get it finished.
Rushing is when mistakes happen (from personal experience!), and even if (absolute worst case) you can't store or work on your armour where you'll be living, there'll be an alternative that lets you carry on with it. Opportunities always present themselves.
Really excited to see your post saying you've got approval!