I can confirm that the rebasing is much faster with IDA 7.4, and it seems to be addressed in version 7.3:
Another debugger related news is fast rebasing. Due to widespread use of ASLR, processes get loaded into a new address every time and IDA needs to adjust the database: move all segments to the addresses that the operating system assigned to them. This ...
The encryption key is stored in the variable f4800b. It comes out to the following byte array.
43, 57, 97, -68, -63, -61, -40, 9, 50, 87, -104, 101, 63, 34, -78, 60
The cipher algorithm used is Triple-DES in ECB mode. It can be decrypted by the following snippet. Note that it requires the BouncyCastle Crypto provider for Java.
They must be stored in some variable or in resources, You can check all the usages for that variable or where that resource was used in the classes, and backtrack and see whatever catches your interests