Troubleshooting: Very slow WAN 2.2 when using loras with intermediate resolutions.

This is a rather peculiar problem, and I haven't been able to find any mention of it through searching. Hopefully I'm not the only one who's encountered it, or at least that someone else might be able to offer some kind of insight.

Essentially, what I'm seeing is that while the bare checkpoint behaves quite normally with regards to the relationship between processing time and video resolution (bigger images = more time), when I attach any lora to it, I see a very nonlinear relationship, with a huge spike in processing time apparently when near the boundary of something fully fitting into VRAM. I gathered some experimental data, presented below:

NO LORA:

320x320:    3.5 s/it
400x400:    5.6 s/it
480x480:    8.9 s/it
560x560:    14 s/it
640x640:    21 s/it
    FIRST MENTION OF "LOADED PARTIALLY"
720x720:    29 s/it, 13127.46 MB usable, 13052.44 MB loaded, 576.63 MB offloaded, 75.01 MB buffer reserved, lowvram patches: 0
800x800:    40 s/it, 10938.44 MB usable, 10858.53 MB loaded, 2770.54 MB offloaded, 75.01 MB buffer reserved, lowvram patches: 0
880x880:    55 s/it, 8513.72 MB usable, 8433.06 MB loaded, 5196.02 MB offloaded, 75.01 MB buffer reserved, lowvram patches: 0

Performance is at first glance consistent; suspect 'lowvram patches' values there are false?
Compare with the LORA case:

320x320:    3.5 s/it
400x400:    5.7 s/it
480x480:    9 s/it
560x560:    14 s/it
640x640:    31 s/it  (! significant divergence begins!)
656x656:    102 s/it
672x672:    165 s/it
688x688:    217 s/it
    FIRST MENTION OF "LOADED PARTIALLY"
704x704:    200 s/it  13526.21 MB usable, 12551.18 MB loaded, 1077.89 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 35
720x720:    169 s/it  13116.05 MB usable, 12133.78 MB loaded, 1495.29 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 51
736x736:    140 s/it  12696.68 MB usable, 11708.70 MB loaded, 1920.38 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 68
752x752:    121 s/it  12268.10 MB usable, 11283.62 MB loaded, 2345.46 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 85
768x768:    106 s/it  11830.29 MB usable, 10855.28 MB loaded, 2773.80 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 102
784x784:    66 s/it   11383.27 MB usable, 10408.25 MB loaded, 3220.83 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 120
800x800:    41 s/it   10927.03 MB usable, 9952.01 MB loaded, 3677.06 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 138
816x816:    44 s/it   10461.58 MB usable, 9483.26 MB loaded, 4145.81 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 157
880x880:    58 s/it   8595.28 MB usable, 7607.90 MB loaded, 6021.18 MB offloaded, 975.01 MB buffer reserved, lowvram patches: 232

I start seeing a significant uptick in processing time at 640x640, although it's bearable at this size; it balloons however rather absurdly and suddenly right around the edge of where we kick over to this 'loaded partially' status. Performance then actually IMPROVES as I continue increasing resolution, until returning to 'normal' at the 800x800 level, after which it slows down again as expected. Perhaps unnecessarily, I made a graph to visualize.

https://preview.redd.it/ujfwnrkgm35g1.png?width=822&format=png&auto=webp&s=2aaf9648dff1f84fb48b6e80f917f7a90ef3c631

Beyond this observation of how the problem manifests, though, I don't have any particular insight into what's going on, and still less how I could hope to fix it. Thusfar I've just been making things bigger or smaller to avoid the problematic resolutions when I hit them. The actual lora used doesn't seem to matter. Any ideas would be appreciated.