i've seen with most updates, with they contain new models they will be released, and the ones you have added in the preious version will be removed, but if it contains no new models you will be fine.
Thats if the 1.1 will be a upgrade like 1.0 to 1.1 if so you should be fine... but if 1.1 is going to be 1 full download it will replace everything which mean you will need to download all the files again for you custom models/spr's