I was messing with the Db11 for fun and my favorite voicing for your situation rn is actually leaving the violin 1 on the Gb and bringing the violin 2 down to the 9th of the chord Eb, it still has all that color of a 11th chord without the clash with the 3rd and 11th. and you get to still have a nice solid 5th in the cello and viola to support the extensions. Try it out lemme know what you think :)