Great to see others interested in LODs, but why are you removing LODs completely? Isn't it enough to make transition distances long enough so that it isn't too visible and fix all those many bugs due to incorrect LOD distances in MODs?
Do Bf-109 in DBW and Ultimate Pack v4 look too bad? I've tried to adjust proper LOD distances for them, and I'm responsible for the difference between v4.09m and UP3/DBW/later. Maybe I was a bit too careful back then and didn't increase LOD distances enough. Anyway, that's mostly outdated now after JapanCat's and Jero's new 3D rework. I've actually forgotten to release my fixed version of Jero's latest Bf-109 update with all LOD distances once again adjusted (longer than before this time, so should look almost perfect) and some other bugs like markings and loadout issues fixed. Thus, I have fixed versions of latest Bf-109 3D models hidden in my DBW install and pretty much finished, but I didn't have time to test properly and release them. Just let me know if you want to help me with testing.
I've also fixed many more planes that I just haven't had time to test properly and release, for example Ki-51 and He-111 with less buggy LODs, P-47 family with many fixes and Lysander, F7F and others that won't disappear way too close anymore. I also started fixing IL-2 LODs that are very ugly, but there's just too many variants to fix in reasonable time without proper tools. Anyway, I've got Il-2MEarly ready for testing if there's someone interested.
There's unfortunately many LOD bugs in mods (gaps, missing parts etc. at different distances) due to bugs in modding tools, and I've used a lot of time to fix at least almost all of them for UP3/DBW and later MODs with many fixes still unreleased. MshConverter 1.16 is actually buggy so that it always disables last LOD due to one missing value in [LOD] section and in many cases (but not all) reads values incorrectly so that they're differences of correct values. There's 1.18 version (possibly still not publicly available) that reads all LOD values but still as differences for most meshes. However, we need batch conversion of meshes from binary to text format to fix LOD issues easily enough, so I hope someone could program tool that converts all binary meshes of complete plane folder to text format easily. Then another simple tool needed is code that just finds [LOD] section in those meshes and replaces values after it with some given values. I privately got one such tool, but it's still buggy so that it messes up all binary meshes without detecting them and replaces also comment lines like "//edit these yourself" with extra LOD value. Thus, a bit better tool for editing LOD values is needed to avoid messing up all binary meshes and comments in [LOD] section so that those meshes won't load anymore in game.
Thus, I have a suggestion for fixing this LOD problem. First, I hope someone could program proper tools that allow easy conversion of meshes from binary to text format and LOD value editing. Then I can start taking requests for planes with bad LODs and fix one family in a couple hours (or less with good tools or small families). For many MODs I may already have fixed version in my DBW install that I've just forgotten to release. I'd like to fix LODs of all buggy planes because I don't want to see those bad LODs anymore but I don't want removal of LODs either.
Unfortunately, HSFX and CUP likely have many of my fixes missing, so there's likely more LOD and other bugs than in UP3/DBW. I just haven't had time to test and fix all that again after all the hard work I did for UP3/DBW, so I hope I would get some help with comparing files and testing all my released and unreleased fixes in CUP. I'm still using DBW because of all those missing fixes and also too many unnecessary plane slots in CUP.
To erafitti: I'd recommend that last LOD value is 2000-4000 depending on the size of plane, otherwise it may switch to dot too close at least at some FOV, resolution and detail level settings. At least for me at normal FOV 1920x1200 max settings LOD value 1000 means 1 km, and dot appears at that distance, so 800 as last LOD value will cause invisible planes at 800-1000 m distance. I hope you'll test my currently unreleased Bf 109 before using too much time for editing more variants. My version likely isn't 100% compatible with v4.09m installs without latest Bf 109 pack installed, though, but fixing compatibility should be a lot better option than editing old 3D.