I’m not sure what you’re asking ?! Appearance rates?!
Loot tier is determined by damage dealt, so are you asking if the damage dealt = reward? Answer - No. Titan loot allocation is completely random. Yes, you’ll get more rolls of loot for A+, but the 4*AMs are just as likely to drop for a C result.
Funny… I always feel I get more loot when I do more damage. So what is your question with regards to appearance rates?
My alliance has been chaining 14* titans since April and we’ve found every titan randomly drops an assortment of 4*AMs. Titan damage is no predictor of the loot you receive.
I remember a poster a while back had gathered a small amount of data that suggested percentages and possible increases at higher tiers, but without Barry levels of data, it is hard to know if that hypothesis has any validity
Unfortunately you’ll never get anything from staff on the subject. The two people you tagged (Zeph and Aqua) are both just players (like me).
I did run a data project (which Rfm linked above) which collected data from thousands of titan loot drops to estimate the drop rates of materials from the titans.
From the thousands of data collection, the drop rate was found to be linked to loot tier not the titan star.
You can read my full results and methodology here:
If you rarely reach A+, A or B on 14* titans of course C will give you a better Loot.
I almost never finish C and the few times I did that - Loot was crap. Does that mean C is crappy for everyone? No.
Do I get a lot of 4* mats on A+, A and B? No. But do I count on all my team-mates to do their best and not go for C when they could have made it to higher damage? U bet.
I’m just tired of hearing that C is so much better Loot. If all players in an alliance go for C - The titans won’t die.
Not wanting to reveal the details about Loot just convinces me that I need to be okay with all my team-mates effort when stacking 14*.
A+ has the better drop rate. That’s just that the drop rate is really low whichever rank you are and people will rank B or C most of the time so statistically they will loot more often with a B or C rank.