Yes, I did think about this and that makes sense to me as well but I generally like to use the given rules rather then house rule something
Unfortunately, there are no official rulings on this, so judgement calls (a.k.a. "house rules") are all there is :/. However...
, especially since I want to have a few custom scenarios around the tentacles so getting this properly sorted will make it easier to put the scenarios on here.
On the contrary, scenarios are where many of the rules are defined or overridden (e.g. Leap skill, Climbing, and Falling damage are all defined in terms of specific scenarios, and sometimes differ from scenario to scenario). Thus providing custom tentacle rules on a per-scenario basis is completely within the game's design.
i.e. IMO defining the tentacle rules to fit the scenario, rather an expecting the core rulebook to do it, is truly the "recommended" approach in this particular game.