It turns out pinterf and I live close to each other, so we took advantage of this and met up in person. We talked about many things, like introductions ofc, what we do for a living, how we got into Avisynth. We also looked at various parts of the code, some parts he still needed to look into, and others that I needed to refresh my own memory about. We also spoke about how important it is that when we get a bug report, we receive a sample video and a minimalistic script to reproduce it. We both felt compelled to point out that a script which has only two lines, but in one of them calls a multi-hundred-line script, is not minimal. We know there are a multiple things to improve and many wishes, but neither of us have the resources to make everything come true, so we need to aggressively prioritize.
pinterf has a lot of development experience, though he only recently started using C++, so he is still experimenting a lot. There are also some other things he's been working on, all related to Avisynth, so you can expect more goodies from him soon
As for me, I have taken home a list of stuff for me to investigate/debug. I'd say once I catch up to this list, pinterf's changes, and Avs 2.6.1, I'll feel comfortable to do another release. Pinterf will probably release other builds earlier.
Of course we went into a lot more detail on each of these topics, but I think this gives you a basic overview of the things we talked about.