My Android build ~~is~~ was quite slow. 3-5 Minutes.
I removed a lot of dependencies and am now able to build without multidex - yay.
Nevertheless I ask myself if setting jumbo mode manually makes any sense...
jumboMode
when enabled it allows a larger number of strings in the dex files https://stackoverflow.com/a/24224385/570168
Q1: Jumbo Mode doesn't have any disadvantages rather it has some advatages.
Jumbo mode pertains to the number of strings that can be referenced in a DEX file, which by default are indexed using 16 bit wide integers. Therefore, if your application encodes more than 2^16 strings, the dx tool will fail as well. For string references however, there is a remedy: DEX supports “jumbo opcodes” which allow for 32 bit wide string references. The jumboMode flag in an Android Gradle build script enables this mode, allowing up to 2^32 strings to be referenced.
What this means is if you have more than 2^16 references in your dex files, you can use jumboMode to accommodate for this by allowing up to 2^32 references. This is done by forcing the byte code to always use "jumbo strings" (2^32) references to help avoid issues when merging dex files.
Q2: It depends on your class files. You can turn it on always if you don't want to worry about it.
Q3: Solely It has not effect on build speed.