Huge thanks to @enolan, who added the source to GitHub:
Alright, go nuts: GitHub - enolan/beescheduler
If you end up getting it running and hosting it somewhere let me know and I’ll replace beeschaeduler.echonolan.net with a long to your thing.
I would love it if @narthur or someone takes this forward and ensures this functionality remains available to the community.
Challenge accepted!
I’ve got something up and running, though haven’t done any testing yet. Use at your own risk. 
Yup, seems pretty broken currently. I’m off for the weekend but hope to get more of the kinks worked out next week.
As the Beescheduler site notes,
WARNING: For technical reasons, any goals you use Beescheduler for will always appear to end in two weeks. The road will end in two weeks when you first set them up, and every day the end date will advance one day, maintaining the two weeks time.
One downside of this is that you can’t set breaks that end in more than two weeks.
(BTW: I can confirm that beescheduler is still working. I have used it consistently for the past 2 years.)
I have long used https://beescheduler.echonolan.net/ to set various rates for various days of the week for my goals. However, the hassle I continually run into is setting weekend breaks over a week in advance. In order to create a break, I have to manually edit the daily rates on beescheduler a week in advance of my break, while staying ahead of the akrasia horizon and counting the days properly so that I always keep 3+ days of buffer on my goal (more of a preference to do it this way, I know I could schedule the weekend breaks for the actual days, but then I get lazy the couple days before the break and have to catch up the couple days after). Then, once I am 8 days away from the end of my break, I adjust the daily rates again so the rates are correct after my break.
I would much rather use a typical do-more goal where setting breaks is much easier, but then I can only do one rate for every day of the week. I know I can get ahead/catch up if I keep enough buffer, but I guess I personally like always hitting green (3 day buffer) and knowing I’m done until the next day or until after my break when the buffer comes back down to 2 days. Also, on some goals (master’s thesis writing/research goal) I am just not motivated enough to get ahead of the beemergency line at all, and so I continually skate on 0 day emergencies to keep myself motivated. If I were to use Beeminder’s typical do more weekly rate, it would not work for this type of goal because I wouldn’t have any flexibility from day to day unless I got enough motivation to get ahead of my lower data days - which I historically don’t… 
Any ideas or thoughts on how to optimize this? I am open to ideas. I see tradeoffs either way.