Learned IR signals are generally not accurate representations of an IR signal.  In fact even the OEM remote is unlikely to be very accurate-- it is cheaper to use components that will provide a remote that works most of the time.

IR signals are just patterns of light flashes, and the pattern is quite systematic. For example Samsung TVs use an IR protocol usually referred to NECx2.  The protocol was defined by NEC of Japan, and they sold chips and licenses to use this protocol.  When a remote sends this signal, it will typically distort the time durations somewhat.  But the TV will still recognize the signal.  If that signal is taught to another remote, the duratons will become more distorted, so with each generation of copies, it becomes more likely that the TV will not recognize the copied IR signal.

However, there are two ways to avoid making copies of learned signals.
1) A learned signal, if it is available to a computer, can be easily decoded.  Subsequently, one can simply supply the decoded signal (e.g. NECx2, device 7.7, function 194 is HDMI3 in a Samsung TV).  Or, even without decoding, one can save the learned signal in Pronto Hex, or Global Cache or LIRT, etc format, and subsequently download that to a new remote.

2) Generally speaking, somebody else has already  experimented to find unpublished discrete codes, and decoded the signals or  recorded them in one of the standard formats.  These get posted here or at hifi-remote.com, and then the rest of us have access.

I don't know about the Prestigo remotes, and what may be required to upload indivdual codes to the remote.  I suppose that there is a way.  I myself (along with lots of folks who hang out at hifi-remote.com/forums) use remotes made by UEI-- for example OneForAll brands.  We buy or make a interface to a 6 pin connector in the remote and upload/download signals.  It isn't even necessary to use a computer interface if the signal in question is from a large manufacturer.  You can manually program a 5 digit number onto a button to get your Samsung HDMI signal.  Here in the USA, people frequently use cable TV remotes with manual programming to control Samsung or other major brand TVs, including signals not included on the OEM remote.

OneForAll makes Xsight Lite and Plus remotes that have a built in USB interface, and you can use the RMIR software to upload/download from those without needing to make/buy an interface cable.