What about also appending the required ilvl onto the displayed tier?

A bit late to the affix tier discussion, buuuuut...

This would help to convey which affix tiers are possible at specific ilvl breakpoints without looking up info from external guides, and by extension, it would make it easier to judge whether you might want to use an Omen of Whittling to improve an item.

Plus, if the ilvl inversion was meant to convey 'bigger = better', putting the raw ilvl requirement there would also help to convey that.

For example, the weakest tier of '%inc phys' on weapons would display as "T8, lv1" while the strongest would appear as "T1, lv82"

yes. absolutely should be how it is since day 0.