Reverse Drury convention is invented to show maximum hand with 3+ card fit with 2♣ bid as a passed hand, when partner opened 1 major in the 3rd or 4th position. Using Reverse Drury convention , we can stop many times in level 2, we get back natural 2NT, 3♣, 3♦ bids, and we can be sure of having or not having fit immediately, what is a great advantage.
We bid 2♣ bid as a passed hand with all 3+ card fit, except Splinter hands, when partner opened 1 major in the 3rd or 4th position. A Splinter bid from passed hand has to consider, that opener may be weaker, than usually. Therefore I suggest to play it only with 4 Italian controls, nice hand and 4 card fit, (not with a poor 4-4-4-1 hand, that should go to delayed Bergen and still we can bid game later) or 3 controls, nice hand and 5 card fit. (Ace is 2 control, King is 1 control)
Reverse Drury is another convention, which has to be changed in order to work better: original Drury convention, although the idea is genial, asked 2♦ with minimum hand, giving the possibility for the defensive side to find ♦ and ♥ fit in level 2, when we have ♠, which is wrong.
Bidding 2♠ with minimum hand, we force left hand opponent to intervene in level 3, although he didn't bid to 1♠, which is much more dangerous.
It is very important to agree not to play Bergen at the same time. We can introduce all maximum hand with 3+ card fit via 2♣ or splinter bids, and we need the natural weak 3♣ bid an the game invitational 3♦ natural bid.
We can play delayed Bergen after 2♣, we bid 3♣ later with singleton and 4 support and 3♦ without singleton and 4 support, instead of natural bids. This solution is working very well.
After 2♣, the 2 major is weak from both sides, 2♦ is an artificial waiting bid, either re-inviting, cca 14 points or slam invit hand.
The new suits from both side will be natural, and the jump bids will be splinter.
It is very important to bid 2 major stop bid to 2♦, when we have bad hand, also when we have an interesting value in our hand. Partner can discover it later, when he needs it, but we cannot stop in 2 major when partner is very weak, and we go above 2 major!
It is also important to find the 4-4 other major fit, because it is very often bringing more tricks, than 5-3 fit. It is easy, when we opened with 1♠, because we simply bid 2♥ instead 2♦ to partner's 2♣, when we have 4+♥.
When we have 4 card ♠ and game forcing hand, we can bid 2♠ to 2♣. When we have to bid 2♦ to 2♣, partner can simply ask our ♠ card number, asking with 2♠ relay.