The Safest Bets for Gen 4 article indicates that the three investments that I have been holding back are actually safe:
A. Gengar with SC/DP (13/15/13), lucky, from level 21 to 30 for many tier 3 solos, notably Jynx and Gengar itself, but also Alolan Raichu and even Alakazam.
B. Snorlax with ZH/BS (14/13/15) from level 15 to 30 for gym defence.
C. Machamp with Ct/CC (15/15/14) from level 15 to 40 as my third maxed Machamp, mainly for attacking Normal-type tanks in gyms, but also for Tyranitar, Absol and Regi raids.
If I spend the 378k dust, I would have just under 1.2 million left. The Gengar and Machamp also need CTMs (I have 18) to be useful.
Although they are safe, I must also save dust and CTMs for my eventual Rhyperiors, Mamoswines, Togekisses, Electivires/Magnezones and of course, legendaries. In addition, I am seeking a 96+% Tyranitar and a 91+% Mewtwo.
Is the next stardust event likely to be in the first week of September? Any important considerations (including other credible speculation) that I overlooked?