Have seen them in all of my regional banks in my area.

Pretty sure they can’t bundle it. AFAIK the libraries required for it ship with Chrome / Android and it’s not an open standard. The hacky weird workarounds are people brute forcing it.

Have noticed this lately, and it absolutely sucks. I’m not a pirate, I just want to be able to purchase books (like I used to physically) and read them at my convenience offline or on any device I like. I’ve been sticking with services where I can do this currently or avoided purchasing those books when I can’t.

Last one I bought (it’s been a year and a half or so) I was able to use Calibre to decrypt it. I do believe the store page has to have a flag saying it’s a digital editions download. I don’t think all offer that IIRC

“Sourcemaps, what’s that?”

IMO I find it really useful in scenarios where you have a set condition that needs to be met (and can always be met so it’s not endless) and looping through to achieve it. I wrote a simple part calculation for a production company I worked for. Essentially while parts_needed < parts packed, pack qty 'x' of part 1, and qty 'x' of part 2 until all parts were filled to the correct amounts. Though it can be done with either / both I just find it more legible.