The biggest issue is there is no easy way to slow them down once they get to their destination, so all you can do it a flyby.
Why wouldn't your solar sail work to slow you down as you approach the 3 star Cenauri system?
The idea is to use lasers to push probes up to speed. But lasers can only push, they can't pull to sloe them down.
There are methods that can be used but nothing that works small scale and cheaply. The 'easiest' would be to build a deceleration array in the target system once you slowboat some construction bots out there.
But frankly... once you have a remote telepresence in another system, why bother to ever send anything there again? Just build stuff there, send AIs and eventually human consciousnesses via radio link at light speed. It will take hundreds of years to send actual human bodies there, we will likely figure out brain uploading before we can build colony ships and get them out there.
Heck, in a hundred years we should easily be able to custom build DNA strands and incubate any living creature on demand. Getting an automated factory out there is all we really need to do.