On our realm we have multiple addons activated. The new style addons you can apply to any world. They worked great until the last update.

Currently the dragon fire addon has broken but others have said it worked fine in solo world. Current issues we see are:

-All dragonfire armor buffs are gone

-Cannot fly dragons 

-No scale drops except for the ones they fixed (nightstalker and nightlight)

-No gravestone or inventory drop if killed by a dragon(resulting in full loss our inventory)

-Lag

Here is the list of free and paid addons we have activated:

-Dragin fire lite

-Dragon fire full paid version

-Spark portals

-Naturalist

-Computers

-Survival mechs

-Decocrafts

-Spark pets 

-Hikers friend

-All the wool 

-Another furniture addon

-Gravestone

-more tnt