Hey I saw the 2 REd Stars on ****. I like 4 5/8th grip and was wondering if it is safe to build them up to that. I have done 4 1/2 before with no issues.
It's definitely do-able, just depends on how you like your racquets. IMHO the Red Stars are light enough and allow a lot of modifications if needed.
Putting two grips sleeves will weigh the butt end down to make it more headlight. If you like leather grips, two sleeves and the grip may be a bit much and will make the racquet too headlight unless you counter it with more lead weights around the hoop, which will end up making the racquet closer to 13 oz overall.
Two sleeves and a regular replacement grip may not be that heavy and might not require much counterweighting the hoop.