Ok, now you've created another dilemma WT and Ingo!
Daytrip (on another day) to Romont (one easy hour/change to bus in Biel) OR keep Zofingen as THAT day's destination? Hmmm...
WT: can Romont's Musee (in the Chateau)be toured independently? I notice guided tours only given on the last Sunday of each month..?

Ok, of course the museum can be visited independently. And wall ramparts to walk? I think Romont is a MUST now! Back to the day schedule to start more juggling (temporary exhibit on Chagall till November 2)!
Only thing is that I only know, like 3 words in French, and some of the town's links to tourism are not in English OR German...tiny bit out of my comfort zone! But thanks for the tip!