I have a few (unrelated to each other) observations to share as I attempt to migrate to V8, and am not sure where to place them, so for now I’ll post to the forum unless advised otherwise:
colorwheel on a tab in a tabview: dragging the knob also attempts to drag the tab too, simultaneously! This can be prevented with lv_obj_clear_flag(wheel, LV_OBJ_FLAG_SCROLL_CHAIN) but I raise this here as this doesn’t seem like desirable default behavior
Message box modal: This is a welcome feature; however, it is created as modal on lv_scr_act(). This doesn’t cover objects on the top layer, which I use and assume others do for the purpose stated in the docs, such as for objects visible across screens
Memory footprint: What is the expectation regarding LVGL memory use for v8, vs. v7? I am using a Teensy 4.1, which has a healthy amount of memory but my app under v7 was pushing it. Directly porting to v8 seems to increase this. I saw approx 137k usage under v7 with the material theme. Under v8, this jumps to 150k with the basic theme and 175k with the default theme. I have reviewed lv_conf.h to check some obvious configuration items are set appropriately (for example LV_USE_LARGE_COORD 0) and nothing stands out
lv_mem_monitor: Can you bring back max_used? In the memory constrained environment of embedded development, the high water mark is just as important as the current usage level, too
auto_realign: Perhaps the one area I’m not convinced is an ‘upgrade’, although I’m sure there are good reasons. This seems to only work if the object is aligned relative to it’s parent? But I have many instances where objects are in a sibling relationship but need to align to each other; say when a labels text shrinks of grows, the sibling next to it needs to budge over a bit. auto_realign took care of this, but now it seems I need to explicitly code for this, also moving some objects to the global scope to allow the reference for align?
themes: I don’t know if it’s even possible for you to preserve themes from release to release, but I’d encourage you to do so. I am sure I am typical of many users who pick a theme that best suits their need, and then run with that with some additional styling, as needed. The thing is, that defines the look and feel of the UI and also the spacing of objects, given the differences in padding, sizes, etc. Moving to v8 and the loss of the material theme means a significant difference in the look and feel of my app, and lots of minor glitches from a spacing/sizing point of view.
Documentation: I found a few areas where the v8 docs haven’t been updated at all, or only partially, and that has made migration a little frustrating (File System is one area that comes to mind) I’d urge a more robust documentation update and review process if you can. You can use all the time you save by not providing any detailed migration documentation of what changed, etc to focus on the main docs 
Finally, I just want to say thanks for all you have done here! I have concentrated on pure migration from v7 to v8 at first (VSCode initially reported 1k+ issues when I switched the library from v7 to v8!) so I have yet to embrace some of the new features, but some look very helpful (event callbacks per event, user data on events, etc). I have mostly completed the functional migration, or have an idea on how to adjust the remaining elements - mostly overall styling and configuring of charts, etc. Performance feels just as snappy and if you can help with the increased memory utilization, I can call it a keeper!
