I want to chime into this as I might be viewed as being obsessed and over the top some times too, I have also overpumped and paid the price by having to ease down, take time off and do a whole lot of skin care to heal discolouration and blisters and its not fun at all. I'm still not done getting it all dealt with.
I try to go on with NBE health first, being impatient and greedy isn't really good combination with this, but moderation is key to success. Health is priceless, boobs take their time and there's gazillion ways to make them grow and there's awesome knwoledgeable people to ask advice from. For me Lotus in particular has been a huge help along with Stevenator and my sweetheart Melissa among others I've talked with on the way. WE only have one health to ruin, breasts are not worth ruining it as our health has no price tag and once its gone it might be horribly difficult to deal with, or even fatal.
So health first, moderation with dosages and no overpumping! I wrote my Noogling guide with this in mind because I have done the mistakes too and I know the damage it can cause but I feel like I've been a cat landing on her feet with averting lot of trouble by digging into how to do it all and its been a lot of trial and error. Also massage is a fantastic aid or replacement for pumping and it wont cause tissue damage at all. To boost growth factors, tiny cell level damage might even be beneficial, but keep in mind that anything that boosts growth factors and elevates growth hormone can also boost cancerous growth! This reminds me that its very timely to get mt breasts checked as soon as I have access to female healthcare. (Stupid bureaucratic shit prevents me until my gender marker gets changed which is in about a month or two.)
About cancer risks, as far as I know, trans women and cis men are quite close the same as where cis women are with it, on HRT we kinda swap one nasty death for another as prostate cancer risk can go down while breast cancer risk goes up. For myself I'm not sure how this works as I'm intersex (More about this later, more evidence has showed up lately.) but I presure the risks are similar to that of a cis woman. Also no breast cancer in family, but its always somewhat a gamble. But lets play smart and not add to the risks! Tissue damage is a certain way to boost growth factors and HGH, these will always raise cancer risk too as they're part of what makes both healthy and cancerous growth happen. And get your boobs screened, it will always be worth it.
Our health is priceless, boobs are awesome, but health is way more important, play smart, not hard.