There's a fair bit of evidence coming out that the original biotransformation that people targeted, i.e. hop oils transformed from one type to another during active fermentation (e.g. geraniol to citranellol), may not make much of a sensory difference. So while it happens, it may not be worth the effort depending on your process. I still do it, but I've really scaled it down and for me it's more about oxidation control than biotransformation.
There's still a few other biotransformations that are being chased by people looking for bigger and different hop flavours. Some of them are hardly even related to fermentation. Thiol release is probably the trendiest at the moment and people are examining process changes focused on mash hopping (with Saaz would you believe?), reducing whirlpool additions and using later and shorter dry hops to maximise the chances of releasing the thiols with the tropical fruit flavours.
Everything is changing every few months in this space, so who knows where the process changes to encourage/discourage different types of biotransformation will settle down? Actually, with the complexity of organic chemistry it's sure to take ages, if it ever does.
On the idea of which hops to use and when and not really related to biotransformation, Yakima Chief have released a great PDF showing the typical compounds in their hops. It then shows how likely these compounds are to survive the various stages in a brew day. So if one compound has got zero chance of surviving the boil, they suggest using hops with a lot of that compound in the dry hop. But if a hop has a fair bit of a compound that survives the boil, think of adding that at ten minutes or flameout. So Azacca should only be used in late dry hop, but Citra is good late in the boil or the active fermentation dry hop.
It also talks about matching hops with different compound profiles. So don't blend two hops with high concentrations of the same compound, look to find two hops with different concentrations. So for their hops, don't blend Loral and Talus, they're too similar. Try Loral and Crystal instead.
To me it's a really helpful document. Just wish we had the profiles for a few of the other hop companies -
https://cryopopblend.com/wp-content/uploads/2021/10/Survivable-Compounds-Handbook.pdf
Some resources if you want to dig into these things more:
