3 months would be reasonably expected as a notice period by any future employer, if you are senior. I can’t see it causing issues if you were to move.
One thing to bear in mind, though, is you would be the only Principal Engineer rather than being in a ‘pool’ of Engineers beforehand. There is no such thing as making a person redundant, only a role. So, if they decided to make an engineer role redundant, they would then have to go through all the process of point scoring to work out who has to go and it might not be the person they want. If they make the Principal Engineer role redundant – well, that’s easy…
Rachel