EDIT EDIT: Lol, I am going to modify some of the info/screens in the post below still in a bit, need a break first though Subtree Rework - Nation Folders - #279 by SilentTracker
Spoiler
EDIT: OK! I think this is correct now, please let me know if there are still any errors, math or concept wise. Thanks!
Some comments about the math, you would need to add the new RP boost % inside of the ( )'s.
Everything inside the ( )'s is additive (all RP boosts currently are), and everything outside of the ( )'s is multiplicative (like the Premium vehicles’ 2.0x SL boost. Which doubles SL boosters, unlike the additive math that RP boosters use).
A 1.1x outside of the ( )'s wouldn’t work as you described. Everything inside the ( )'s is always added together before the external multipliers are factored in ( PEMDAS ).
Your 1.1x multiplier math shown below:
(I used Wolfram Alpha to make sure of your initial math, which is correct, the result would be 765.6%)
However, 1.1x like you have outside of the ( )'s would be a multiplier. And, it would not be 10%. An increase from 660% to 766% = an increase of 16.06%:
(I am using Wolfram Alpha to prevent errors on my part.)
Conversely, if you did add an extra 100% inside the ( )'s, the result would be 928%
2.32x(100%+100%[premium time]+100%[Talisman]+100%[New proposed boost])
2.32x(400%) = 928%
IF your intent is to add a simple 10% RP boost, then you would add it inside of the ( )'s:
Resulting overall % increase in RP boost from 660% to 719.2% = overall increase of 8.97% (This resulting overall % increase is always going to be a bit funny, as the RP multiplier to the left of the ( )'s changes depending on the BR of the vehicle.) But the resulting overall % boost is much closer to 10%, compared to adding a 1.1x to the outside of the ( )'s.
Even if you added a 2.0x RP boost outside of the ( )'s it would never be an added 100%, it would be a 2x multiplier to everything else previously added up inside the ( )'s making a proposed RP boost wildly high 🙂
So, if you are intending to only increase the gain by 10%, you would simply add in an extra 10% inside of the ( )'s, not 100%, nor 110%. And absolutely nothing outside of the ( )'s. You cannot add a % outside of the ( )'s because it would instead be turned into an intensely powerful multiplier. (And again, 1.1x outside of the ( )'s does not = 10%, it is well over 10% “because of the math” lol.)
UNLESS that is your intent, but the resulting boost would be much higher than 10%, especially at higher BR’s where the normal RP multiplier outside of the ( )'s gets higher.
TL;DR: Percent boosts go inside the ( )'s, multipliers go outside the ( )'s 👍