Re CECB choking on PSIP:
I know of only one CECB that chokes on too much PSIP: Dish TR40 (probably the TR40+ as well). Ironic if Dish is the main sticking point to getting more PSIP for the TR50.
Choking on PSIP was IMO an Echostar design flaw -- the TR40 loads even deleted channels into the guide. And I had more than most, 35 subchannels, generally with 3 days PSIP, and 2 stations (7 subchannels) went out 6-7 days. I am not sure how the TR40 prioritized stations for the guide, but my biggest data hog, a deleted station, was among the first to load. It had 5 subchannels, 7+ days of PSIP, and even worse, someone at the station from time to time entered 20-30 'programs' per hour. No kidding. The TR40 supposedly deletes expired guide in standby and downloads at startup. But it seemed to pause at startup, deleting future guide info as it tried to make room. That's when I got lockups, not often, but not 100% reliable. The main hassle was if I wanted guide info on a channel that loaded after the memory was full, I had to sit on that channel for half an hour to get the guide info to load.
None of my other CECBs choked on data. Most weren't designed to show much guide, but my Zinwell Zat (with the 'hidden' bonus EPG) could accept 16 days PSIP. The most I ever saw was 8 days, but it also went backwards, which was occasionally useful. It took longer to fill the guide a week out, but it never locked up.
These days, my stations don't show as much PSIP. The 6 day station now shows 3 days, 1 day is common, and there are a couple 12 hour PSIPs as well. Things tend to fall apart on the weekend. Even so, if we can overcome any reluctance to let the TR40 choke itself, PSIP may be the best chance for a guide. Without a week, the search function is useless.