Advice on Lower Control Arm damage & repair

[VX KAT]

FYI when I had my diff drop brackets installed I opted for new upper ball joints & my mechanic installed MOOG life-time guaranteed "made in USA" ones. The only thing I kinda was disappointed with is they have the zerks so unlike the factory ones you gotta grease them on occassion. Yeah, I know, I got lazy with the original ones being no maintenance,,,lol.

Actually Merlin mentioned that brand for the lower ball joint when we were discussing these, he said they'd be les$, but I decided to just go with the OEM, one stop shopping, done, no worrying about right part or fit etc?.

Here's a weird question I thought of?.my used lower ball joint rubber boot was starting to show signs of getting dried out - so that means my other side is no doubt doing the same, and some day they're gong to split I presume.
Could you spray some FLEXSEAL ("rubber in a can") on the boot to add some life? or would it get too hot to handle that? or some other problem?