Options for knee locks

[Icarus]

I am learning to walk with an RGO (might as well assume the question applies to KAFOs ) The unit uses drop locks on the knees which require that the knees be locked before I stand and remain locked when I am returning to a seating position. Both of these but especially the act of sitting down is awkward. In an ideal world I would be able to unlock the knees into a mode which would not swing loose but allow slow bending so my legs are not hels rigid as I am getting down.
In an evem more ideal world I might be able to lock the knees after I am up although that might require strength I do not have to straighten the knee.
Is anyone aware of options in Knee locks??