Question: How save is the merging of plugins in the following situation?
There's an already big (and I mean really big) .esp file, around 6 MB, with tons of information and some plugins depending on it. FormIDs of it must not change therefore.
Now I want to build a new worldspace, and when the worldspace is finished, merge it into the above mentioned .esp.
If I set the priority of the merge files to [1] for the first and [2] for the second, will FormIDs of mod 1 stay the same?
Are there any known or suspected cases where using the Clean Plugin feature breaks a mod? And if so, what should I look out for?
I ask for two reasons. One, I've seen occassional postings where people have alleged that TES4Gecko Clean Plugin broke their mod; and two, I thought I had run into the same issue myself, but it turned out that I just had to rebuild my Bashed patch after cleaning it. Go figure.
You shouldn't believe anything you've been told. Judge yourself. In the end everyone is just stating opinions, though some are based on facts and knowledge, others on myths and misunderstandings.
So, keeping this in mind...:
1. Imho the tes4edit cleaning should be used. When it comes to cleaning they do the same thing (i.e. comparing the plugin with their master, then removing what's duplicated and therefore identical to master) - but tes4edit has a way better memory usage (e.g. when cleaning Integration: TSL. tes4gecko chokes on it, while tes4edit doesn't on my system), and tes4edit lists all changes and creates a backup file.
2. There exists something which I would call "identical to master by design" situations. There are a few in FCOM, there are a few in LAME. They're usually there to prevent problems with potentially earlier loaded mods which may cause bad mod interaction otherwise. Those shouldn't be cleaned out. Though they're extremely rare exceptions.
3. Cleaning does remove records that are identical to master. While there are some that claim that automatical cleaning has destroyed their mods, they never were able to show any kind of evidence. Evidence which would be very easy to produce. Furthermore those claims often came from people that made mods with a wide varietey of dirt, like e.g. issues associated with Recompile All Script or Generate All Pathgrids. If you ask me, those claims are likely defensive excuses to not learn how to use external tools - and until I see an actual evidence of a mod destroyed by cleaning it with tes4edit, I won't believe these claims. Note however that I say tes4edit - as mentioned tes4gecko can choke on some massive .esp files, and I don't think it's healthy if that happens during saving the plugin).
So in short: Use tes4edit's cleaning, if only because it's more memory efficient and automatically creates a backup file
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