New dictionary and new boards

[lalatan]

rosedraws: both words are listed in whatever dictionary Google search uses. Both are archaic.
MEDICABLE: able to be treated or cured medically
IMMEDICABLE: unable to be healed or treated; incurable.
I think if one is accepted, so should the other one. Nevertheless, your scenario could be true; it is English, after all. I'll let Stephen be the arbitrator on this issue. His opinion is the only one that matters on this website.

Stephen, ROENTGENOTHERAPEUTICALLY, ROENTGENOTHERAPEUTICAL, ROENTGENOTHERAPEUTIC were accepted but the spelling RONTGENOTHERAPEUTICALLY is rejected. I didn't test the 2 shorter words.

[rosedraws]

immedicableness but not medicableness? Probably more a quirk of the English language than a quirk of the Wordtwist dictionary...

[lalatan]

On a recently played board, ENSIFEROUSNESS(ES) and ENSIFEROUS were not accepted. Neither was SENSIFEROUSNESS nor SENSIFEROUS.

[BoggleOtaku]

Surprised GLUTINATION(S) were not accepted. Seems to be a medical term for gluing or sealing up a wound.

[lalatan]

Although it's a term used for making explosives more stable, PHLEGMATISATION and its plural were not accepted.

On another board PALAEODENDROLOGIST(S) were accepted but not PALEODENDROLOGIST(S).

PERVERTEDNESSES was accepted but not UNPERVERTEDNESSES.

NONFICTITIOUSNESS(ES) AND FICTITIOUSNESS(ES) were rejected.

On a 4x4 board OVERRECRUITMENTS was valid but not the singular.

On a 4x4 board MISADMINISTERING was accepted but not MISADMINISTER.

[DrPlacebo]

Another missing word.

I got points for ARCHAEOBOTANICAL (30), ARCHAEOBOTANICALLY (34), and ARCHEOBOTANICALLY (32). However, the American ARCHEOBOTANICAL is missing.

[Spike1007]

PHOSPHORYLATE and PHOSPHORYLATES weren't accepted.

On the other hand, HYPERPHOSPHORYLATE is accepted.

[jbud1980]

Tjoeb Lollapaloozas. Amazing find, and such a great event with amazing bands/artists.

[lalatan]

PHOSPHORYLATE and PHOSPHORYLATES weren't accepted.

[lalatan]

ORGANOGENICALLY, ORGANOGENICAL and ORGANOGENIC were not accepted.

[sadied]

TOWNCRIER wasn't accepted.

[Spike1007]

I don't know if this will make the list, but MICROSPECTROGRAPHIC doesn't work while ULTRAMICROSPECTROGRAPHIC does.

[Spike1007]

AGGRESSIVENESS and HYPERAGGRESSIVE both work, but HYPERAGGRESSIVENESS doesn't.

[BoggleOtaku]

SUPERDREADNOUGHT accepted. I tried SUPERDREADNOUGHTS twice but was rushed, so I think not accepted but am not sure.

[BoggleOtaku]

All forms of PALEO+ANTHROPOLOGIC+AL+LY work except ANTHROPOLOGIC