Okay, I don't know if I am the only one doing this, but whoever wants this, I suggest you try to adjust your hand a bit and do as I do.
The red circle shows the part of my hand that I hold ctlr with, leaving my thumb and little finger in air basically, but all the 3 that are left I can still use pretty efficiently. This way, even though hand can't be moved too freely, if you adjust it properly, I believe it still is better than holding down ctrl with small finger alone. With some training I believe it is more comfortable.
OR, you can do the old coin trick and just make ctrl be stuck and have it on at all times.