Really? Odd. I thought some level of mixed-dev bundling was possible, but then maybe that's only for special circumstances that itch.io itself sets.
Well, if you put up a bundle with
BAD END WONDERLAND
Late Night Delivery
Late Night Delivery 2
The Making of Late Night Delivery 2! - Interactive Art Pack
...that cost about $6.00, I would be interested, because I would still possibly like the old versions of the games available. Maybe only in that bundle, but it would still be nice.
But hey, whatever works.