Hi Amy,
SO good that you have further info to define things. A great start point to address concerns.
but NEVER is not an open start point.
And lug boot is not familiar term, other than sole design, as on hiking or the walking sole of AT or the newer WTR type designs for alpine.
I'm more familiar with traditional 'overlap' design like your ProMachines, Cabrio/Mid-Entry/Panel design like Full Tilt, and re-emerging Rear-Entry - not mentioning some exotics...
So, I don't recommend 'never', be open to considerations.
So here's what you know now, 23 mondo foot length, 80 mm width (all numbers same for both feet?), and 21.5 instep (my preferred measure method for instep is from heel over instep back to heel - most used over the years; as opposed to perpendicular from sole over instep back to sole... which was used on you?)
So, was your arch length measured? I consider arch length a critical measurement in boot model and shell sizing.
Instep is also critical in model and shell sizing.
Given your known numbers, the 23 mondo and 80 ish width means a slightly narrow forefoot width for the foot length - not excessive.
21.5 instep measured heel/instep/heel is a slighty lower instep - midpoint avg stats say instep = mondo length - give or take - your instep might be normal/average for women that size, if instep measured close to your 23 mondo.
Arch length would now factor in greatly to make further refinements for model search and sizing.
IE - my numbers
mondo length - 28.4 RT, 28.6 LF, instep 32.6 RT 33.0 LF cm, arch length 21.0 RT 21.2 LF cm, forefoot width 98 RT 99 LF mm
what this tells me is my super tall instep and super long arch length and narrow feet will be deciding factors on model/fit (my heel width also needs consideration...)
Hopefully you're not equating your quite normalish forefoot width with 'std last size' one hears for boot models... It's a mistake so many others make.
'Std last size' quoted for most mens/unisex models comes from mens 9.5 / 10 size - mondo 26/26.5 . That's the '95', '98', '102' width you hear and read about for ski boot models. The actual 'last size' for any actual boot size will vary greatly from 'std last'. Especially variations from mens to womens models. Most HiPro models will be last sized closer to 'womens' width in sizing below 25, for good reason. Your ProMachines in your current boot/shell size are certainly NOT last sized to the '98' you hear about them. Nor would that be true for larger sizes like 28,29,30...
Given a slightly narrower forefoot and lower instep foot (instep measurement method considered) controlling your foot inside the boot is a major consideration. That also means controlling the stacking orientation at the ankle.
I would highly recommend considering good orthotic footbeds to mate to whatever you decide to do about boots.
A good orthotic footbed which takes up a bit of volume might even help greatly with your current boots; given consideration for effective overall ramp angle changes.
Good luck with your quest for solutions!