The short answer: Your C64 consumes a bit more power for nothing.
LumaTOLB is designed to offer a solution for older boards which do not use the 7701/8701 and have problems with their clock generator which is designed around a cluster of discreet logic ICs. Since there probably is a signal coming out of these chips, good or bad, and they can't be removed easily like the 7701/8701, they must be disconnected from the VIC-II to avoid some sort of tug of war between them and the TOLB components.
For this reason, LumaTOLB is missing pins 21 and 22 (see the two X near C4 on the 3D image of the bottom layer). This is where the clock signal generated either by a 7701/8701 or the cluster of logic chips older boards carry comes into the VIC-II. Since LumaTOLB feeds the clock signals directly to the VIC-II it carries, these pins are no longer needed. Cutting them prevents conflicting signals.
If you use LumaTOLB on a board which has a socket for the 7701/8701, you can just remove it and sell it. It's outputs won't be connected to anything anymore.
If I understand this correctly the LumaTOLB could also be used on the C64 Reloaded MKII and get rid of the WiModem interference issue?