you may be ok regarding damaging equipment, but, that is pushing things beyond normal.
using 8 ohm tap for 16 ohm speakers boosts the midrange frequencies which you may like (voices are here), or want tone controls to adjust things (be conservative).
most pre-amps have simple bass or treble controls, (i.e. not midrange tone controls) and we hear less highs as we age, so boosting highs can be less problematic than boosting bass which is the primary source of room interactions. boosting both bass and treble to balance with midrange is not a situation I would want.
see the graph in this link
http://blog.hughes-and-kettner.com/ohm-cooking-101-understanding-amps-speakers-and-impedance/
excerpt (so don't overdo it)
using 8 ohm tap for 16 ohm speakers boosts the midrange frequencies which you may like (voices are here), or want tone controls to adjust things (be conservative).
most pre-amps have simple bass or treble controls, (i.e. not midrange tone controls) and we hear less highs as we age, so boosting highs can be less problematic than boosting bass which is the primary source of room interactions. boosting both bass and treble to balance with midrange is not a situation I would want.
see the graph in this link
http://blog.hughes-and-kettner.com/ohm-cooking-101-understanding-amps-speakers-and-impedance/
excerpt (so don't overdo it)
Case 1: running a 16 ohm speaker with an 8 ohm amp output
With this combination, the voltage at the speaker output will rise, while the current will almost halve. The power will drop, although you probably won’t notice it too much, as this combination will likely increase the mids in your tone. So long as you don’t overdo it – make it a rule of thumb not to connect a speaker with more than double the output impedance of that of the amp – this method can be quite useful, as you can effectively boost the mids in a cab that might otherwise be lacking in this department.