When partner opens 1 or 1 and you have opening bid values, it is best to get into a 2/1 GF auction when possible. When the opening is 1, however, and you have 5+ spades, you can't suppress the suit; you have to start with 1 and catch up later.
What if you have opening bid values and support for partner? With 3-card support, start with a 2/1 in your longest suit. Your 2/1 response promises at least 4 cards. The auction 1-2 is the only 2/1 response which guarantees 5+ cards. Yes, you are stuck in the exact situation where partner opens 1 and you have a 3=4=3=3 GF. You will have to tell some lie (I prefer 2 on the 3-card suit). However, I like to play 1M-3NT as a balanced 13-15 (3 trumps and any 4-3-3 in the other suits), so that can often solve the 3=4=3=3 dilemma.
With 4-card support for partner I prefer to show it right away (either via a Jacoby 2NT or a Splinter-raise if in range). A Splinter-raise shows 4 trumps, 0-1 in the suit and about 12-15 in support. With more, don't use a Splinter bid (start with Jacoby 2NT).
Remember, that 2/1 GF is off in interference (if they double or overcall). It is also off (of course) if the responder is a passed hand.
Partner deals and opens 1. RHO Passes. What is your response with:
KJ765
A42
AQ
K32
1
1NT
2
2
2NT
Other
Partner deals and opens 1. RHO Passes. What is your response with:
K65
AQ42
AQJ3
32
2
2NT
3
Other
Partner deals and opens 1. RHO Passes. What is your response with:
K765
42
AQ2
AKQ2
1
1NT
2
Other
Partner deals and opens 1. RHO Passes. What is your response with:
KJ765
2
AQ2
J832
1NT
2
2NT
3
4
4
Partner deals and opens 1. RHO Passes. What is your response with:
AQ65
AK42
2
A932
1NT
2
2
2NT
4