No, you don't need it. Multiple relative clauses or adjectives can independently modify a noun without being connected in 連用形.
行ったことのない、新しいお店
綺麗な、青い鳥
白衣を着た、痩せた男
These are all valid.
I would also say that in this case it sounds more natural to not be 連用形 because if it were, it would have a nuance like 刺激的 is a result of 匂いに負けない, when if anything it's the reverse.
刺激的で、匂いに負けない味 would also work fine here.