First of all, if you don't know what suburito is, it is a heavy shinai/bokuto to increase the strength and speed of your cut.
Probably, many of you want to use a suburi-to.
That is a very good idea only if you can handle the weight of a any swords including suburi-to.
If you cannot handle the weight of a suburi-to, most likely you try to use your right arm to control the suburi-to.
It turns your kendo into a very right-handed kendo. Therefore, it is not wise to use a suburi-to until you have a correctly established cutting form.
It is often said, "Do a lot of suburi with a light shinai until it gets heavier".
Of course, the shinai doesn't actually get heavier but since your wrists, arms and shoulders get tired by a lot of suburi or cuts, you cannot lift your shinai anymore.
If you plan to do kendo as long as you live, I think that is the way for you. After thousands of thousands of cuts, you can finally learn how to relax and how to control your shinai.
Once you establish a solid cutting form, it will not be deformed by the weight of a suburito easily.
I wouldn’t say “at all”. If you really want to use a suburi-to, swing it very slowly as if you were checking your cutting form.
If you swing a suburi-to really fast you will lose the control of it. And you will try to stop your suburi-to by using the strength of your right hand.
This is the bad part.
So slow down your cut. And then stop it at the right height of men or kote or whatever you are aiming at. Speed up the process as you are getting used to the weight.
Hope this helps.