Spicing your cholent on Shabbos

This came up recently at our table. So I looked around a bit and found in Yesodei Yeshurun, p. 96,that the Zekan Aharon (2:21) was asked if one can pour cold soup onto hot potatoes in a keli sheni, and he wrote that the Maharshal (Shach, YD 105:5) who paskens that a davar gush is in a mevashel in a keli sheni is not oisgehalten l'ma'aseh - and especially not b'makom Oneg Shabbos. Moreover, he says, even the Maharshal only meant that it is mavli'a and maflit in Issur va'Heter, but not that it is actually mevashel, so it is not relevant to Hilchos Shabbos in any event!