Underdrive Pulley Questions

[DRGETZ]

Considering Pedro's Underdrive Pulley Kit but read that IMS Bearing Replacement should be done before because of the need to shave down the "boss" or Top Dead Center bolt receiver/holder/whatever (not sure of technical term).

Can someone elaborate on why shaving down the "boss" may make this more difficult?

Can enough of the "hole" be left intact to use it as a TDC guide?

Any other problems experienced as a result of an Underdrive Pulley Kit?

Recommend any other kit over Pedro's and why?

Thanks in advance.