Hi. I’ve been using LO for years. I have several PCs & a laptop running a mixture of Win10 and Linux. What I would like to know is whether there is a single ‘transplantable’ file or folder in LO which I could copy to a new install which would bring over all the changes I that have made over time to my existing installs of LO. I know that updates seem to keep this information, so could it be somehow ‘transplanted’ into a clean install ?
Your question is ambiguous by lack of descriptions about your “changes”.
For “operational” changes like modifying the default styles, create a template file which you can store in /home/<user>/Templates/ under Linux (there is certainly an equivalent under Windows). Make it the default template so that it is automatically used when you create a new document.
It should be possible to store it in a “system” directory so that it is available to all users on your machine but this would require fiddling with “system” locations and it could be overwritten or erased on updates. So prefer simple and reliable solutions.
For UI changes such as modifying the composition of toolbars, menus or shortcuts, this is stored in the user profile. Although you could copy this user profile from one machine to the other, refrain from doing it. There are subtle differences between releases and perhaps between OSes which can lead to hard-to-fix problems.
In principle, if you work intensively with styles, you really need UI actions (menus or shortcuts) rather rarely.