The Tachihara can focus a 65mm on a flat board? The Shen HZX bellows is fully compressed with a 90 on a flat board?

I'm about to talk myself back into the Tach. It would be nice to be able to go even shorter than 65 for use with a rollfilm back, but one can't have everything in one camera.

How much trouble is swapping the bellows on the Shen, and what is the LONGEST lens that can focus (infinity I guess) with the bag? I'm wondering if it might be practical for me to just leave the bag on it. My longest lens currently is a 203 Ektar, though I'd like something longer, but I know anything longer will need the regular bellows (and probably the Ektar. I'm guessing maybe 150 or so is max with the bag?)