Note that the OSR has a higher speed capability, while many scripts might be limited to the handy, a lot of them still go excessive as they rely on the player to limit the movement. This makes those scripts still work better on the OSR.
Higher speeds might in most cases not realy be needed, but especialy in fast up/down strokes, this speed does allow you to smooth the curves a bit
And where you say fleshlight sleeves require you to be hard. My experience is that some of the handy sleeves are worse (especialy lotus) as they tend to push you back out unless you modify the sleeve to have a hole to release excess air.
But otherwise just invest in a (cheap) penis pump, as that usualy is enough to get it hard without any effort. For most people just a little vaccuum does enough.
Its indeed sad that the extra axis is often wasted, but this is the downside of the OSR being expensive, the cheaper these devices get, the more people that buy them, and the more will be scripted for it. Maybe they will find a way that will convert the plain up/down movement into a more natural movement that requires a bit more axises to be used. As in the end, even for the most basic movements in sex you already use more axises.
Its that i dont have an OSR, but that would be one of the first things that i would look for, and potentialy even script myself (converting an existing script in OFS towards this specific movement, and then merge the scripts again).
I can tell without having the experience of the OSR that such extra movements can do a lot. As good as the handy is, it in the end does still feel artificial as the motion is extremely linear. Which already made me often avoid videos that try to be realistic as it wont feel realistic anyway. To me its an excelent CH and PMV device, but for imitating actual sex, it misses these extra movements.