ICAO leaves two options for countries when choosing this level. Countries can require vertical separation between an aircraft at the transition level and the transition altitude and thus the transition layer will be a minimum of 1000ft. With this system you can indeed have a transition level of FL45 (i.e. an intermediate 500ft) however, in such a situation, ATC will often use a whole FL as the minimum crusing or holding level.
You can listen to the ATIS at Baden (EDSB) on +49 72 29 66 23 32. The transition altitude from the AIP is 5000 ft. Here's the METAR.
METAR EDSB 162020Z 21008KT 8000 -RA SCT038 BKN044 08/04 Q1005=
The transition level is clearly stated on the ATIS as "FL70". If multiples of 500 ft were used, the transition level would be FL65, as this provides 1000 ft separation from 5000 ft.
I have never in 15 years of flying in Germany (or anywhere else I recall hearing the TL on ATIS) heard a transition level of anything other than a multiple of 1000 ft.
Since we're agreed that TL is essentially meaningless, it's of academic interest.