For those of you who bought AF3 custom packs including presets from older packs made under fw 16.xx, here's a quick guide to update them and optimize them for fw 20.xx:
The most significative and relevant tweaks in order to get the presets to sound right are "high mids" in the drive block and "low cut frequency" in the preamp page of the amp block.
High mids in the drive block defaults to 0, and should be set to 5 instead.
Low cut frequency defaults to 500ish and should be set to 10Hz instead.
These 2 tweaks should already do the trick and give you a pleasant and convincing tone. If you want to deep dive in the advanced parameters, here's a tip for further enhancement: select an unused channel on the amp block (e.g. D), load the Class-A30tb model, take a look at the advanced parameters (take a note, write them down, memorize them, whatever you prefer!), select the actual channel the preset uses (e.g. A) and tweak those parameters with the values you just got from the new fw default settings. These tweaks are very subtle (for example, bias excursion on your older preset will default to 104% as opposed to 100%), no one will ever be able to tell, but you can judge for yourself!
These tips are also true for FM3 and FM9, although these processors do mostly default to correct settings when importing older presets into the latest fw, but a double check won't hurt!
Don't forget about the Black Friday promo running until Monday 28, use code BF2022 for a 15% discount on all products until then!