the exam going computer-based would have me worried about conceptual ideas. I've heard from some of the more recent environmental PE's in my office said they'll ask specific questions like when an act was approved which could be simply answered with some references, but with it being closed book made it a memory thing.The bolded is NCEES speak for 'the questions/content aren't changing much'
See commentary above.
I'm not sure if having a consolidated reference source, with a ctrl-f searchable function makes it more difficult or easier. And recall that the reference material is provided months ahead of time so the examinee can use it when studying for the exam.
If they prepared the reference correctly and cross checked the reference correctly, then the examinee will have the required raw information (codes, tables, equations, etc) required to answer the problems. They'll still have to rely on skill and experience to answer questions. OTOH the exam committee will (read: should) also remove any questions that could be answered by the reference with a simple ctrl-f search.
In addition to that, I have to worry for my Transpo people about how bad trying to use the HCM portion may be since you're seeking the same objective but in multiple different forms (i.e. urban road, city road, highway segment, etc.). I feel like that'll trip people up if they aren't aware and stay cognisant of it.