The following extract from a French AIC may help.
“In order to know whether to look at "baro-aided" or "non baro-aided" predictions, it is necessary to know whether a barometric altitude input is provided or not to the installation aboard the aircraft of interest.
RAIM availability demands that a minimum number of satellites be received. Barometric aiding reduces this number by one.”
That is why the RAIM prediction tools show different results for baro-aided and non baro-aided. Using the Augur prediction tool for my home airfield often shows short non baro-aided outages for RAIM prediction but so far as not shown an outage for baro-aided.