I have a 1236T on order as well. It's a real disappointment they don't tell you this. One of the critical dimensions. I've asked sales and their tech and neither will tell you. I'm lead to believe it's slightly different between each one or there's some reason they are intentional about not saying. It's not like they haven't had hundreds of these go through their warehouse to measure one. It's certainly just barely in the BXA size range for Aloris specs sizing chart. For dorian I believe it falls in what is considered their AXA size, but their sizing seems different than most.
I don't believe the toolpost size per say is what really matters, it's how low can you get your tooling to be on centerline, so the tool holder is really important. The bottom shelf of the tool holder plus your tooling shank size etc..... You can order PM's XL (3/4") holders which lowers the tool bit a bit, but even then PM's specs advertised for their XL holders is inaccurate. I can post actual dimensions of their XL holders if you wish. I just ordered a couple.
I messaged someone else about the compound to center line and was told it's 1.2" so that's on track with
@Ischgl99's measurements.
Not recommended, but I've banked on it being BXA and without the lathe yet I've ordered the Aloris BXA (they have 20% off this month) and a bunch of tooling from Curtis at latheinserts.com... all 5/8" shank so hope it works out
. I have yet to order a parting blade, other than the 5/8" shank one from latheinserts.com (all suggestions from
@davidpbest's book) except the aloris #77 or #71 style holder because I'm hesitant on the blade height getting low enough.
As I just came to my senses... your multifix tool post setup is different, so the most common Aloris style and their knockoff tool holders isn't really of concern for you.