The frame and a traditional fork with braces will not really be an issue. They are overbuilt. Many of these old frames were used on early mountain bikes because of their extraordinary strength.
Where I would be concerned is wherever a spring is used - suspension fork, saddle, etc. In choosing a spring, one has to decide how stiff, gauge of the wire, etc. A spring that is ideal for a 110 pound child is going to be too light for a 180 pound adult rider. A spring that is ideal for a 180 pound adult will be too stiff to be effective with a 110 pound child. So I would look closely at your suspension fork spring, saddle springs, etc. if weight is an issue for you. You may need to swap to heavier spring in the suspension fork, and consider heavy-sprung saddles that have braided springs in back.
The plain flat blade fork has a different issue. It's strong fore-aft, but flexible from side-to-side. You'll see this if you bank hard into a turn, where the front wheel moves slightly entering and leaving the bank. If you're particularly heavy, I'd consider a different fork or bracing of some sort if you to a lot of hard banked turns that flex the blade fork left-right.