Can Add-on be batch downloaded in later update?

[patz]

Need the function badly as there are many add-on like UMC music 1-12, too much time taken on repeatedly download every one of them each time.

[Pentarctagon]

That functionality does not currently exist, no.

[Soliton]

You can download multiple addons with the wesnoth_addon_manager. You can find it under data/tools. To download all UMC music addons you can use -d UMC_Music_Book.* as arguments for example.

I don't know what you mean by repeatedly downloading the same addons. If you mean you downloaded the addons for a different version then specifically the UMC music addons you can likely just copy over from the other version instead of downloading them again. That's less likely to work well with other addons though.

[egallager]

From the add-on publisher's perspective: one could also upload "meta-addons" to the add-on server that simply list all of the desired add-ons as dependencies.