Your design current will change, 9500w/230v=41.3A and 10500/230=45.7A and depending on the type of circuit protector you are using (mcb/fuse). It could effect the size of the cable to be installed. As you will need a 50A rated Fuse/mcb. Don't want to get to technical. But that's the problem with changing from 9.5 to 10.5kw.
As for dangerous, VERY if not correctly installed bathrooms are covered by part p of building regs and must be installed to comply with them. Not a DIY job really! you need a part p electrician.
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