As i see it if you don't plan to immediately grant to help with your vassal limit(which also has it dangers) then no you shouldn't. As Haly said all it will do is lead to is people gunning for pretty much every kingdom title you have. Which can lead to some nasty scenarios like fighting multiple civil wars over different titles.
Wish I had read this and similar advice earlier
I'm trying different things in CK2 to keep it fresh, so on my most recent playthrough I started as Croatia - it looked like a region with interesting possibilities. I gobbled up the independent provinces nearby early on and formed the Kingdom of Serbia, and then (in the spirit of trying something new) swore fealty to the Byzantine Empire. And how great it was! Now, instead of fighting the Byzantians, I could fight as a Byzantian! My lands sprawled from the northern border of Greece to the duchy of Wallachia (and if it wasn't for a last second conversion to Orthodoxy by the Pechenegs, I would have had Moldau as well). It was a simple matter of time until I grew powerful enough to claim the purple for myself.
Now, for reasons too boring to get into, I hadn't been able to implement primogeniture yet, so I'd been doing electoral succession as an interim measure. This was working pretty well until both of my sons died (after I ventured an uncuessful civil war to lower crown authority, I had been castrated (!) so more sons weren't an option). I still had a couple daughters, one of whom was matrilineally married. Alright, then. But while I could nominate my youngest daughter as the next leader of the glorious Kingdoms of Serbia and Croatia, I couldn't give any landed titles to that daughter (I didn't know how to change that, either). Serbia only had like, two voters, and I was one of them, so that was fine - but I was a vote short in Croatia, which by far was the larger kingdom.
Aha! I thought. I'll just make my son-in-law a duke - surely he will vote to make himself the future spouse of the depost of Croatia! No. No he didn't, the stupid idiot. He supported one of the rivals for the throne, making me two votes short.
My last-chance gamble to plot the death of my own son-in-law, so I could remarry my daughter to someone more inclined to support my dynasty. However, before I could achieve this, someone poisoned the elderly eunuch despot of Croatia and Serbia. Almost all of my holdings passed out of my control to the new despot of Croatia, while I took on the mantle of the Queen Despot of Serbia, with like 6 provinces total and a demense of 1.