You're right, that makes no sense, and needs to be bug reported aggressively.
You've got 2 sets of % in fusion:
(%A): % chance of fusion success or failure. This can be 100% for fusions up to legendary quality if you put enough items in the cauldron. % for mythic fuses maxes out at 63% for 5x legendaries, or is 50% for 4x legendaries, or lower with 2 or 3.
(%B): % chance of a specific outcome, provided the fuse is successful. The total % chance of all possibilities here always adds up to 100%
The put-put and turkey decorations are described as increasing % chance of fusion success by 1%. By definition, fusion success % is (%A) above, and the point of this decoration would be a minor bump to mythical fusion success, or reduce the failure % chance for lower level fuses with less items used.
The original implementation of put-put had 2 bugs. First, it did not modify (%A). Second, it did change (%B) so totals added up to more than 100%.
The latest patch appears to have corrected the second bug (%B adding up to more than 100%), but it did nothing to address the fact that the decorations do not modify the overall % of success/fail of a fusion (%A above). Now we have two premium decoration items that we've purchased with real money that still do not work as advertised.
Darkis, you've said earlier that fusion and put-put are now working as intended. I would appreciate some feedback on whether this is actually true based on the clarifications above - it feels like the original bug fix mistakenly only flagged the (%B) error, and nothing has been said that I can see about the (%A) error.
As it stands, it appears that put-put and turkey decorations do absolutely nothing, and that's not what we bought. I've already submitted a ticket to support, but have not received a reply yet.