I don’t take baclofen but my sister did. The thing to watch for is sometimes spasticity can mask weakness a bit. She found that eliminating the spasticity made walking difficult as the weakness is her legs had been counterbalanced somewhat by spasticity. Her solution while she still walked was baclofen at bedtime to relieve night time spasticity. Later when she was full time in a chair she took it in the day too.
You won’t know until you try if this is an issue with walking or transfers for you
There shouldn't be too much of an issue. If you work up your dosage you will get used to it. Like was said, it is a balance between relaxing the muscles and maintaining some spasticity if it is helping you. It made me sluggish for a while.