The purpose of the rear (single) and front (double) lugs is to provide additional bearing surface(s) for the receiver against the stock.
Since few, if any stocks are inletted for these features, you will either have to DIY, or pay to have it done. It will also be necessary to glass bed the stock, once inletted, to take advantage of these features. Again, DIY or pay.
I'm no expert, but I suspect that these features do offer some additional support, and also extend the service life of the bedding job.
Whether or not the additional expense and complication is worth it is up to you.
An alternative might be to bed your conventional action into a USGI synthetic stock.