With Colina, I kind of see him as being in a window where you're probably not going to be too worried about his options anyway. There are a lot of other pitchers in this system on a similar timeline, so I don't think you need to milk every ounce of service time/protect options for each and every one of them. But, that's just me, that's a very subjective take, not necessarily the "right" one.
It's too bad Alcala hasn't taken off as a reliever because he'd be the perfect guy to go to in this conversation otherwise.
Again, it's not so much about Colina's own options or service time, but rather protecting other player assets. Adding Colina to the 40-man now could leave a player like Jax, Blankenhorn, etc. unprotected this winter (or leave us with less flexibility to claim the next Kirby Yates ).
I haven't crunched the numbers recently -- maybe we have enough spots to protect everyone we want this winter and still protect Colina.
But having just added Dobnak, planning to add Graterol soon, and hopefully bringing back Thorpe and considering Duran, we also have to consider how much opportunity we could even give Colina in MLB right now.