I’d either take an increase in drop rate or for some of these hard-to-farm MIs to guarantee a rare affix, both changes might make it too easy to get good (but not BiS) MIs a bit too easy to obtain. That said though, I agree with the sentiment that getting a Vigorous Chains of Ordas of Mending or similar as a drop is pretty disappointing.
It’s also worth considering which MIs can be bought from vendors around the world as these are easier to farm than ones that can only be dropped.
Loxmere’s spawn rate combined with the chance of equipping multiple daggers is nicely tuned against how accessible he is. Increasing his spawn rate could only come with a decrease to loxblade equip rates or we’d have the grandest outlier of an MI drop rate that you could not match others to without having them drop multiple copies each kill.
Being able to check lox roughly once a minute at a (vaguely remembering) 60% spawn rate and a combined 58% chance to equip daggers yields an effective drop rate around 35% per run. Or something like 3 min per loxblade. Consider that you need two vs. a 2hander setup and we can extrapolate this to 6 min per a single general piece which feels about right when you look at the time it takes to clear most roguelikes (except the thrice damned PV)