Oooh, thanks - I'll have a tinker. I can't get my head around the geometry for the thumb for either type of hand.
Been working Arex's 'below decks'
Added the hip ball to the back of the hips and rotated the hip socket to run front to back rather than sideways. Need to remove some of the 'crotch' to allow the leg to pivot forward or backwards. I realised I modelled the knee backwards though 🫣
The first pic is how his leg should look, but is very gappy. The second looks better to me, despite being 'wrong'. All 3 knees would bend backwards as per usual, with a hoof style foot to get the 'S' bend shape - the back foot might need to be at a different angle to balance him. Either angle could have what would normally be the inside leg cut out made smaller, as per the red dotted line to look better from the front.
His extra leg has the range and direction of motion as the regular two, which is tricky, but not impossible, to do on a minimate. The 2D animation sort of warps depending on what's needed, so I don't believe he would ever be able to sit down as he's shown doing- he'll be standing at a bridge station anyway as Chekov will be a the helm anyway.