Indeed. The PLA is still not ready with its power projection capabilities.The problem here is they still try to picture China's long term strategic planning on what they would do. In their mind if you sign a security agreement with a country it's because you want to build a military base.
But a PLAN base in Solomon Island doesn't make much sense at this time. While power projection capability of PLAAF and PLAN have greatly improved Solomon Islands all the way in south pacific seems a bit far for a secure base.
China's game plan here is the old silver bullet > lead bullet, winning without fighting thing. Prove to the other island nations that if you ditch ROC and sign up with PRC you will get plenty of economic development. Then they will one by one jump onboard similar arrangements and you end up with a string of China friendly nations all the way to South America, then once it spreads there as well it will be even harder to isolate China.
However, in the meantime, you can still do plenty of things with replenishment at the port in SoloMon Islands.
A base could happen 6-10 years later.
For now, intelligence gathering, training, showing the flag missions, and grayzone warfare would be more suitable.